Signal coordinated delivery of laser therapy

ABSTRACT

Systems, devices, and methods for delivering laser energy directed toward target tissue using a spectroscopic feedback. An exemplary laser feedback control system comprises a feedback analyzer to receive a signal from a target tissue using a spectroscopic sensor, and a laser controller to determine whether the received signal generally equals a first preset. If the received signal meets the first preset, the laser controller can send a control signal to a laser system to change from a first state to a second state of the first laser system. The laser system can deliver laser energy via an optical fiber towards the target tissue.

CLAIM OF PRIORITY

This application claims the benefit of priority under 35 U.S.C. § 119(e)of U.S. Provisional Patent Application Ser. No. 62/882,837, filed onAug. 5, 2019, U.S. Provisional Patent Application Ser. No. 62/894,226,filed on Aug. 30, 2019, and U.S. Provisional Patent Application Ser. No.63/027,090, filed on May 19, 2020, which are herein incorporated byreference in their entireties.

TECHNICAL FIELD

This document relates generally to endoscopic laser systems, and morespecifically relates to systems and methods for controlling laser energydelivered to a target based on a spectroscopic feedback.

BACKGROUND

Endoscopes are typically used to provide access to an internal locationof a subject such that a physician is provided with visual access. Anendoscope is normally inserted into a patient's body, delivers light toa target (e.g., a target anatomy or object) being examined, and collectslight reflected from the object. The reflected light carries informationabout the object being examined. Some endoscopes include a workingchannel through which the operator can perform suction or passinstruments such as brushes, biopsy needles or forceps, or performminimally invasive surgery to remove unwanted tissue or foreign objectsfrom the body of the patient.

Laser or plasma systems have been used for delivering surgical laserenergy to various target treatment areas such as soft or hard tissue.Examples of the laser therapy include ablation, coagulation,vaporization, fragmentation, etc. In lithotripsy applications, laser hasbeen used to break down calculi structures in kidney, gallbladder,ureter, among other stone-forming regions, or to ablate large calculiinto smaller fragments.

SUMMARY

The present document describes systems, devices, and methods fordelivering laser energy directed toward target tissue using aspectroscopic feedback. An exemplary laser feedback control systemcomprises a feedback analyzer to receive a signal from a target tissueusing a spectroscopic sensor, and a laser controller to determinewhether the received signal generally equals a first preset. If thereceived signal meets the first preset, the laser controller can send acontrol signal to a laser system to change from a first state to asecond state of the first laser system. The laser system can deliverlaser energy via an optical fiber towards the target tissue.

Example 1 is a laser feedback control system coupled to a first lasersystem configured to deliver laser energy directed toward a targettissue. The laser feedback control system comprises: a feedback analyzerfor receiving signals from a target tissue using a spectroscopic sensor,the signals comprising a first signal indicative of one or morespectroscopic properties of a target tissue; and a laser controller inoperative communication with each of the feedback analyzer and the firstlaser system, the laser controller being configured to: receive thefirst signal from the feedback analyzer; determine whether the firstsignal generally equals a first preset; and if the first signal meets afirst preset, send a first control signal to the first laser system tochange from a first state of the first laser system to a second statethe first laser system.

In Example 2, the subject matter of Example 1 optionally includes,wherein the laser controller is further configured to receive a secondsignal from the feedback analyzer, the second signal being distinct fromthe first signal.

In Example 3, the subject matter of Example 2 optionally includes,wherein the laser controller is further configured to send a secondcontrol signal to the first laser system to change from the second stateof the first laser system to the first state of the first laser systemif the second signal generally equals a second preset.

In Example 4, the subject matter of any one or more of Examples 2-3optionally includes, wherein the laser feedback control system isconfigured to be connectable to a second laser system distinct from thefirst laser system.

In Example 5, the subject matter of Example 4 optionally includes,wherein, the laser controller is configured to independently control thefirst laser system and the second laser system.

In Example 6, the subject matter of Example 5 optionally includes,wherein, the laser controller is configured to send a third controlsignal to the second laser system to change from a first state of thesecond laser system to a second state of the second laser system if thesecond signal generally equals a second preset.

In Example 7, the subject matter of Example 6 optionally includes,wherein, the laser controller is configured to send a fourth controlsignal to the second laser system to change from the second state of thesecond laser system to the first state of the second laser system if thelaser controller determines that the first signal generally equals thefirst preset.

In Example 8, the subject matter of Example 7 optionally includes,wherein, if the laser controller determines that the first signal meetsthe first preset, the laser controller is configured to send: the firstcontrol signal to the first laser system, thereby changing the firstlaser system from the first state of the first laser system to thesecond state of the first laser system; and the fourth control signal tothe second laser system, thereby changing the second laser system fromthe second state of the second laser system to the first state of thesecond laser system.

In Example 9, the subject matter of Example 8 optionally includes,wherein, if the laser controller determines that the second signal meetsthe second preset, the laser controller is configured to send: thesecond control signal to the first laser system, thereby changing thefirst laser system from the second state of the first laser system tothe first state of the first laser system; and the third control signalto the second laser system, thereby changing the second laser systemfrom the first state of the second laser system to the second state ofthe second laser system.

In Example 10, the subject matter of any one or more of Examples 1-9optionally includes, wherein the spectroscopic sensor includes at leastone of: an imaging camera; a Fourier Transform Infrared (FTIR)spectrometer; a Raman spectrometer; a UV-VIS reflection spectrometer; ora fluorescent spectrometer.

In Example 11, the subject matter of any one or more of Examples 1-10optionally includes a signal detection optical fiber operatively coupledto the spectroscopic sensor, the signal detection optical fiber beingconfigured to transmit the first signal from the target tissue to thespectroscopic sensor.

In Example 12, the subject matter of any one or more of Examples 1-11optionally includes, wherein the spectroscopic sensor is in operativecommunication with a first optical fiber of the first laser system, thespectroscopic sensor being configured to detect the first signal via thefirst optical fiber of the first laser system.

Example 13 is a laser treatment system that comprises: a first lasersystem, comprising: a first laser source, and a first optical fiberoperatively coupled the first laser source, the first optical fiberbeing configured to deliver energy from the first laser source toward atarget tissue; and a laser feedback control system coupled to the firstlaser system, the laser feedback control system comprising: a feedbackanalyzer for receiving signals from the target tissue, the signalscomprising a first signal indicative of one or more spectroscopicproperties of the target tissue; and a laser controller in operativecommunication with each of the feedback analyzer and the first lasersystem, the laser controller being configured to receive the firstsignal from the feedback analyzer, to determine whether the first signalis generally equal to a first preset, and to send a first control signalto the first laser system to change from a first state of the firstlaser system to a second state the first laser system.

In Example 14, the subject matter of Example 13 optionally includes asecond laser system that includes a second laser source in operativecommunication with the first optical fiber.

In Example 15, the subject matter of Example 14 optionally includes,wherein the first laser source is configured to generate a first laseroutput over a first wavelength range, and the second laser source isconfigured to generate a second laser output over a second wavelengthrange, distinct from the first wavelength range.

In Example 16, the subject matter of Example 15 optionally includes,wherein the first wavelength range corresponds to at least a portion ofan absorption spectrum of the target tissue, and the second wavelengthrange corresponds to at least a portion of an absorption spectrum ofcarbonized tissue.

In Example 17, the subject matter of any one or more of Examples 14-16optionally includes, wherein the second laser system is controllable bythe laser controller, such that upon receipt of control signals from thelaser controller, the second laser system changes from a first state ofthe second laser system to a second state of the second laser system, orfrom the second state of the second laser system to the first state ofthe second laser system.

In Example 18, the subject matter of any one or more of Examples 14-17optionally includes, wherein the first state of each of the first lasersystem and the second laser system corresponds to generation of a firstlaser output by the first laser source and a second laser output by asecond laser source respectively.

In Example 19, the subject matter of any one or more of Examples 14-18optionally includes, wherein the second state of each of the first lasersystem and the second laser system corresponds to a state where thefirst laser source and the second laser source each do not generate alaser output.

Example 20 is a method of controlling a laser treatment systemcomprising a first laser system. The method comprises: receiving, usinga feedback analyzer, signals from a target tissue, the signalscomprising a first signal indicative of one or more spectroscopicproperties of a target tissue; determining, using a laser controller,whether the first signal is generally equal to a first preset; andsending a first control signal to the first laser system to change froma first state of the first laser system to a second state the firstlaser system if the first signal is generally equal to the first preset.

In Example 21, the subject matter of Example 20 optionally includes,wherein the first signal is indicative of the target tissue beingcarbonized by absorption of a first laser output from the first lasersystem.

In Example 22, the subject matter of Example 21 optionally includes,wherein the first state of the first laser system corresponds to a statewhen the first laser system generates the first laser output, and thesecond state of the first laser system corresponds to a state when thefirst laser system does not generate the first laser output.

In Example 23, the subject matter of any one or more of Examples 20-22optionally includes, wherein the signals received by the feedbackanalyzer comprises a second signal distinct from the first signal.

This summary is an overview of some of the teachings of the presentapplication and not intended to be an exclusive or exhaustive treatmentof the present subject matter. Further details about the present subjectmatter are found in the detailed description and appended claims. Otheraspects of the disclosure will be apparent to persons skilled in the artupon reading and understanding the following detailed description andviewing the drawings that form a part thereof, each of which are not tobe taken in a limiting sense. The scope of the present disclosure isdefined by the appended claims and their legal equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are illustrated by way of example in the figures ofthe accompanying drawings. Such embodiments are demonstrative and notintended to be exhaustive or exclusive embodiments of the presentsubject matter.

FIG. 1 illustrates a schematic of an exemplary laser treatment systemincluding a laser feedback control system.

FIGS. 2A-2B illustrate examples of absorption spectra of different typesof tissue including hemoglobin (Hb) and oxyhemoglobin (HbO₂).

FIGS. 3A-3C illustrates examples of absorption spectra of differenttypes of tissue including normal tissue and carbonized tissue, Hb, HbO₂,and melanin.

FIG. 4 is a diagram illustrating penetration depths of a laser output.

FIG. 5 is a block diagram illustrating a laser feedback control systemfor providing laser output.

FIGS. 6-7 are flow diagrams illustrating examples of algorithms forcontrolling one or more laser systems based on the feedback generated bya laser feedback control system.

FIG. 8 illustrates a timing diagram of an exemplary dual laser systemproviding tissue ablation and coagulation using two optical wavelengths.

FIGS. 9A-9B illustrate an example of an endoscope with a laser fiberinserted.

FIGS. 10A-10B illustrate examples of feedback-controlled laser treatmentsystems.

FIGS. 11A-11B are diagrams illustrating examples of an endoscopic systemfor identifying a target using a diagnostic beam such as a laser beam.

FIGS. 12 and 13A-13B are diagrams illustrating reflectance spectra foridentifying target types, such as for identifying compositions ofdifferent types of kidney stones.

FIGS. 14-15 illustrate light peaks corresponding to different sectionsof the UV wavelength and the reflectance spectra of the several types ofstones in FIGS. 13A-13B.

FIGS. 16A-16B illustrate examples of reflectance spectra captured on aUV-VIS spectrometer from various soft and hard tissue compositions.

FIG. 16C illustrates examples of FTIR spectra of typical stonecompositions.

FIG. 16D illustrates examples of FTIR spectra of some soft and hardtissue compositions.

FIGS. 17-18 illustrate schematic diagrams of a laser treatment system.

FIGS. 19A-19B illustrates examples of a combined laser pulse traingenerated using a number of (e.g., N) laser pulse trains.

FIG. 20 illustrates a schematic of an exemplary spectroscopic systemwith spectroscopic feedback.

FIGS. 21A-21D illustrate examples of an endoscopic laser system withmulti-fiber configuration.

FIG. 22 is a block diagram illustrating an example of a multi-fibersystem as used in a spectroscopic fiber delivery system.

FIGS. 23A-23B illustrate examples of a multi-fiber accessory with sourcelight input and spectroscopy feedback signal.

FIGS. 24A-24D are diagrams illustrating exemplary methods of calculatinga distance between the distal end of the laser delivery system (e.g., anoptical fiber) and the target.

FIGS. 25A-25B illustrate an impact of distances between the tissue andspectroscopic probe distal end on the spectra of the reflect light fromthe target.

FIG. 26 illustrates an example of an endoscope system for identifying atarget using a diagnostic beam such as a laser beam.

FIG. 27 illustrates a graph of a sequence of laser pulses havingdifferent pulsed energy or power levels for use in laser treatment oftarget tissue or calculi structures.

FIG. 28 is a block diagram illustrating an example machine upon whichany one or more of the techniques (e.g., methodologies) discussed hereinmay perform.

DETAILED DESCRIPTION

Described herein are systems, devices, and methods for delivering laserenergy directed toward target tissue using a spectroscopic feedback. Anexemplary laser feedback control system comprises a feedback analyzer toreceive a signal from a target tissue using a spectroscopic sensor, anda laser controller to determine whether the received signal generallyequals a first preset. If the received signal meets the first preset,the laser controller can send a control signal to a laser system tochange from a first state to a second state of the first laser system.The laser system can deliver laser energy via an optical fiber towardsthe target tissue.

In endoscopic laser therapy, it is desirable to recognize differenttissue, apply laser energy only to target treatment structures (e.g.,cancerous tissue, or a particular calculus type), and avoid or reduceexposing non-treatment tissue (e.g., normal tissue) to laserirradiation. Conventionally, the recognition of a target treatmentstructure of interest is performed manually by an operator, such as byvisualizing the target surgical site and its surrounding environmentthrough an endoscope. Such a manual approach can lack accuracy at leastin some cases, such as due to a tight access to an operation site thatoffers a limited surgical view, and may not determine composition of thetarget. Biopsy techniques have been used to extract the target structure(e.g., tissue) out of the body to analyze its composition in vitro.However, in many clinical applications, it is desirable to determinetissue composition in vivo to reduce surgery time and complexity andimprove therapy efficacy. For example, in laser lithotripsy that applieslaser to break apart or dust calculi, automatic and in vivo recognitionof calculi of a particular type (e.g., chemical composition of a kidneyor pancreobiliary or gallbladder stone) and distinguishing it fromsurrounding tissue would allow a physician to adjust a laser setting(e.g., power, exposure time, or firing angle) to more effectively ablatethe target stone, while at the same time avoiding irradiatingnon-treatment tissue neighboring the target stone.

Conventional endoscopic laser therapy also has a limitation that tissuetype (e.g., composition) cannot be continuously monitored in aprocedure. There are many moving parts during an endoscopic procedure,and the tissue viewed at from the endoscope may change throughout theprocedure. Because the conventional biopsy techniques require theremoval of a tissue sample to identify the composition, they cannotmonitor the composition of the tissue throughout the procedure.Continuous monitoring and recognition of structure type (e.g., soft orhard tissue type, normal tissue versus cancerous tissue, or compositionof calculi structures) at the tip of the endoscope may give physiciansmore information to better adapt the treatment during the procedure. Forexample, if a physician is dusting a renal calculi that has a hardsurface, but a soft core, continuous tissue composition informationthrough the endoscope can allow the physician to adjust the lasersetting based on the continuously detected stone surface composition,such as from a first setting that perform better on the hard surface ofthe stone to a second different setting that perform better on the softcore of the stone.

Some features as described herein may provide methods and apparatus thatcan identify the composition of various targets, for instance, inmedical applications (e.g., soft or hard tissue) in vivo through anendoscope. This may allow the user to continuously monitor thecomposition of the target viewed through the endoscope throughout theprocedure. This also has the ability to be used in combination with alaser system where the method may send feedback to the laser system toadjust the settings based on the composition of the target. This featuremay allow for the instant adjustment of laser settings within a setrange of the original laser setting selected by the user.

Some features as described herein may be used to provide a system andmethod that measures differences, such as the chemical composition of atarget, in vivo and suggests laser settings or automatically adjustslaser settings to better achieve a desired effect. Examples of targetsand applications include laser lithotripsy of renal calculi and laserincision or vaporization of soft tissue. In one example, three majorcomponents are provided: the laser, the spectroscopy system, and thefeedback analyzer. In an example, a controller of the laser system mayautomatically program laser therapy with appropriate laser parametersettings based on target composition. In an example, the laser may becontrolled based on a machine learning algorithm trained withspectroscope data. Additionally or alternatively, a user (e.g., aphysician) may receive an indication of target type continuously duringthe procedure, and be prompted to adjust the laser setting. By adjustinglaser settings and adapting the laser therapy to composition portions ofa single calculus target, stone ablation or dusting procedure can beperformed faster and in a more energy-efficient manner.

Some features as described herein may provide systems and methods forproviding data inputs to the feedback analyzer to include internetconnectivity, and connectivity to other surgical devices with ameasuring function. Additionally, the laser system may provide inputdata to another system such as an image processor whereby the proceduremonitor may display information to the user relevant to the medicalprocedure. One example of this is to more clearly identify differentsoft tissues in the field of view during a procedure, vasculature,capsular tissue, and different chemical compositions in the same target,such as a stone for example.

Some features as described herein may provide systems and methods foridentifying different target types, such as different tissue types, ordifferent calculi types. In some cases, a single calculus structure(e.g., a kidney, bladder, pancreobiliary, or gallbladder stone) may havetwo or more different compositions throughout its volume, such asbrushite, calcium phosphate (CaP), dihydrate calcium oxalate (COD),monohydrate calcium oxalate (COM), magnesium ammonium phosphate (MAP),or a cholesterol-based or a uric acid-based calculus structure. Forexample, a target calculus structure may include a first portion of CODand a second portion of COM. According to one aspect, the presentdocument describes a system and a method for continuously identifyingdifferent compositions contained in a single target (e.g., a singlestone) based on continuously collection and analysis of spectroscopicdata in vivo. The treatment (e.g., laser therapy) may be adapted inaccordance with the identified target composition. For example, inresponse to an identification of a first composition (e.g., COD) in atarget stone, the laser system may be programmed with a first laserparameter setting (e.g., power, exposure time, or firing angle, etc.)and deliver laser beams accordingly to ablate or dust the first portion.Spectroscopic data may be continuously collected and analyzed during thelaser therapy. In response to an identification of a second composition(e.g., COM) different than the first composition in the same targetstone being treated, the laser therapy may be adjusted such as byprogramming the laser system with a second laser parameter settingdifferent from the laser parameter setting (e.g., difference power, orexposure time, or firing angle, etc.), and delivering laser beamsaccordingly to ablate or dust the second portion of the same targetstone. In some examples, multiple different laser sources may beincluded in the laser system. Stone portions of different compositionsmay be treated by different laser sources. The appropriate laser to usemay be determined by the identification of stone type.

Some features as described herein may be used in relation to a lasersystem for various applications where it may be advantageous toincorporate different types of laser sources. For instance, the featuresdescribed herein may be suitable in industrial or medical settings, suchas medical diagnostic, therapeutic and surgical procedures. Features asdescribed herein may be used in regard to an endoscope, laser surgery,laser lithotripsy, laser settings, and/or spectroscopy.

FIG. 1 illustrates a schematic of an exemplary laser treatment systemincluding a laser feedback control system 100 according to illustrativeexamples of the present disclosure. Example applications of the laserfeedback control system 100 include integration into laser systems formany applications, such as industrial and/or medical applications fortreatment of soft (e.g., non-calcified) or hard (e.g., calcified)tissue, or calculi structures such as kidney or pancreobiliary orgallbladder stones. For instance, systems and methods disclosed hereinmay be useful for delivering precisely controlled therapeutic treatment,such as ablation, coagulation, vaporization, and the like, or ablating,fragmenting, or dusting calculi structures.

Referring to FIG. 1, the laser feedback control system 100 may be inoperative communication with one or more laser systems. While FIG. 1shows the laser feedback system connected to a first laser system 102and optionally (shown in dotted lines) to a second laser system 104,additional laser systems are contemplated within the scope of thepresent disclosure.

The first laser system 102 may include a first laser source 106, andassociated components such as power supply, display, cooling systems andthe like. The first laser system 102 may also include a first opticalfiber 108 operatively coupled with the first laser source 106. The firstoptical fiber 108 may be configured for transmission of laser outputsfrom the first laser source 106 to the target tissue 122.

In one example, the first laser source 106 may be configured to providea first output 110. The first output 110 may extend over a firstwavelength range. According to some aspects of the present disclosure,the first wavelength range may correspond to a portion of the absorptionspectrum of the target tissue 122. The absorption spectrum representsabsorption coefficients at a range of laser wavelengths. FIG. 2Aillustrates by way of example an absorption spectrum of water 210. FIG.2B illustrates by way of example an absorption spectrum of oxyhemoglobin221 and an absorption spectrum of hemoglobin 222. In such examples, thefirst output 110 may advantageously provide effective ablation and/orcarbonation of the target tissue 122 since the first output 110 is overa wavelength range that corresponds to the absorption spectrum of thetissue.

For instance, the first laser source 106 may be configured such that thefirst output 110 emitted at the first wavelength range corresponds tohigh absorption (e.g., exceeding about 250 cm⁻¹) of the incident firstoutput 110 by the tissue. In example aspects, the first laser source 106may emit first output 110 between about 1900 nanometers and about 3000nanometers (e.g., corresponding to high absorption by water) and/orbetween about 400 nanometers and about 520 nanometers (e.g.,corresponding to high absorption by oxy-hemoglobin and/ordeoxy-hemoglobin). Appreciably, there are two main mechanisms of lightinteraction with a tissue: absorption and scattering. When theabsorption of a tissue is high (absorption coefficient exceeding 250cm⁻¹) the first absorption mechanism dominates, and when the absorptionis low (absorption coefficient less than 250 cm⁻¹), for example lasersat 800-1100 nm wavelength range, the scattering mechanism dominates.

Various commercially available medical-grade laser systems may besuitable for the first laser source 106. For instance, semiconductorlasers such as InXGa1-XN semiconductor lasers providing the first output110 in the first wavelength range of about 515 nanometers and about 520nanometers, or between about 370 nanometers and about 493 nanometers maybe used. Alternatively, infrared (IR) lasers such as those summarized inTable 1 below may be used.

TABLE 1 Example List of suitable IR lasers for the first laser source106 Absorption Optical Wavelength Coefficient Penetration Depth Laser λ(nm) μ₂ (cm⁻¹) δ (μm) Thulium fiber laser: 1908  88/150 114/67  Thuliumfiber laser: 1940 120/135 83/75 Thulium:YAG: 2010 62/60 161/167Holmium:YAG: 2120 24/24 417/417 Erbium:YAG: 2940 12,000/1,000   1/10

Referring to FIG. 1, the laser treatment system of the presentdisclosure may optionally include a second laser system 104. The secondlaser system 104, as mentioned previously, includes a second lasersource 116 for providing a second output 120, and associated components,such as power supply, display, cooling systems and the like. The secondlaser system 104 may either be operatively separated from or, in thealternative, operatively coupled to the first laser source 106. In someexamples, the second laser system 104 may include a second optical fiber118 (separate from the first optical fiber 108) operatively coupled tothe second laser source 116 for transmitting the second output 120.Alternatively, the first optical fiber 108 may be configured to transmitboth the first output 110 and the second output 120.

In certain aspects, the second output 120 may extend over a secondwavelength range, distinct from the first wavelength range. Accordingly,there may not be any overlap between the first wavelength range and thesecond wavelength range. Alternatively, the first wavelength range andthe second wavelength range may have at least a partial overlap witheach other. According to some aspects of the present disclosure, thesecond wavelength range may not correspond to portions of the absorptionspectrum of the target tissue 122 where incident radiation is stronglyabsorbed (e.g., as illustrated in FIG. 2) by tissue that has not beenpreviously ablated or carbonized. In some such aspects, the secondoutput 120 may advantageously not ablate uncarbonized tissue. Further,in another example, the second output 120 may ablate carbonized tissuethat has been previously ablated. In additional examples, the secondoutput 120 may provide additional therapeutic effects. For instance, thesecond output 120 may be more suitable for coagulating tissue or bloodvessels.

A laser emission may be highly absorbed by soft or hard tissue, stone,etc. By way of example, FIGS. 3A-3C illustrate absorption spectra ofdifferent tissue types. FIG. 3A illustrates absorption spectrum ofnormal tissue (prior to ablation) 311 and that of carbonized tissue(after ablation) 312, respectively. FIG. 3B illustrates that within acertain wavelength range (e.g., 450-850 nm), the absorption spectrumfollows an exponential decay with the laser wavelength. (Source of datashown in FIGS. 3A and 3B: http://omlc.org/spectra/hemoglobin/). FIG. 3Cillustrates optical absorption spectra measured in different media,including spectra for water 331A-331C (at 75%, 100%, and 4%concentration, respectively), spectra for hemoglobin (Hb) 332, spectrafor oxyhemoglobin (HbO₂) 333, and spectra for melanin 334A-334D (forvolume fractions of melanosomes in 2%, 13%, 30%, and 100%,respectively). (Source of data shown in FIG. 3C,http://www.americanlaserstudyclub.org/laser-surgery-education/). Thewavelengths for water absorption are in the range of 1900 nm to 3000 nm.The wavelengths for oxyhemoglobin and/or oxyhemoglobin are in the rangeof 400 nm to 520 nm. Though many surgical lasers are highly absorbed inwater or hemoglobin, inside a scope, there is limited media to absorbthe water, which may be a reason for the inside of an endoscope maybecome damaged by laser energy.

FIG. 4 illustrates the penetration depth of a laser output such as thesecond output 120. (Source of data shown in FIG. 4:http://www.americanlaserstudyclub.org/laser-surgery-education/). As seentherein, the second output 120 may be suitable for effective coagulationdue to a penetration depth comparable to characteristic dimensions of asmall capillary (e.g., between about 5 and about 10 μm). Furthermore, incertain examples, referring to FIGS. 3A and 3B, the second wavelengthrange may correspond to low absorption of the second output 120 bytissue that has not been carbonized, but high absorption by tissue thathas been carbonized (e.g., by ablation of the first output 110).Appreciably, the spectral characteristics of the second output 120correspond to high (e.g., greater than about 250 cm⁻¹) absorption of theincident second output 120 by carbonized tissue. Examples of suitablesecond laser sources include Ga_(X)Al_(1-X)As with second output 120 inthe second wavelength range of between about 750 nanometer and about 850nanometer, or In_(X)Ga_(1-X)As with the second output 120 in the secondwavelength range of between about 904 nanometer and about 1065nanometer.

While two laser systems with partially overlapping spectra suitable forabsorption by tissue (normal and/or carbonized) are described above, inalternative examples, instead of the second laser system 104, the firstlaser system 102 may provide the second output 120. In an example, thefirst laser system 102 may provide a first output 110 over the firstwavelength range suitable for high absorption by “normal” tissue thathas not been previously ablated (e.g., as illustrated in FIG. 2), andthe second output 120 over the second wavelength range corresponding tolow absorption by tissue prior to being carbonized, and/or more suitablefor coagulation (e.g., as shown in FIGS. 3A and 3B). The first lasersystem 102 may provide additional outputs over additional wavelengthranges.

Reference is again made to FIG. 1. According to example examples, thelaser treatment system includes a laser feedback control system 100.Referring now to FIG. 5, as described previously, the laser feedbackcontrol system 100 may analyze feedback signals 130 from a target tissue122 and control the first laser system 102 and/or the second lasersystem 104 to generate suitable laser outputs for providing a desiredtherapeutic effect. For instance, the laser feedback control system 100may monitor properties of the target tissue 122 during a therapeuticprocedure (e.g., ablation) to determine if the tissue was suitablyablated prior to another therapeutic procedure (e.g., coagulation ofblood vessels). Accordingly, the laser feedback control system 100 mayinclude a feedback analyzer 140.

With continued reference to FIG. 5, the feedback analyzer 140 may,according to one example, monitor spectroscopic properties of thetissue. Spectroscopic properties may include characteristics such asreflectivity, absorption index, and the like. Accordingly, the feedbackanalyzer 140 may include a spectroscopic sensor 142. The spectroscopicsensor 142 may include a Fourier Transform Infrared spectrometer (FTIR),a Raman spectrometer, a UV-VIS reflection spectrometer, a fluorescentspectrometer, and the like. The FTIR is a method used for routine, easyand rapid materials analysis. This technique has relatively good spatialresolution and gives information about the chemical composition of thematerial. The Raman spectroscopy has good accuracy in identifying hardand soft tissue components. As a high spatial resolution technique, itis also useful for determining distribution of components within atarget. The UV-VIS reflection spectroscopy is a method that gathersinformation from the light reflected off an object similar to theinformation yielded from the eye or a color image made by a highresolution camera, but more quantitatively and objectively. Thereflection spectroscopy offers information about the material sincelight reflection and absorption depends on its chemical composition andsurface properties. It is also possible to get unique information aboutboth surface and bulk properties of the sample using this technique. Thereflection spectroscopy can be a valuable technique to recognizecomposition of hard or soft tissue. The fluorescent spectroscopy a typeof electromagnetic spectroscopy that analyzes fluorescence from asample. It involves using a beam of light, usually ultraviolet, thatexcites a material compound and causes the material compound to emitlight, typically in visible or IR area. The method is applicable foranalysis of some organic components such as hard and soft tissue.

The feedback analyzer 140 may include optionally, an imaging sensor 144(e.g., CCD or CMOS camera sensitive in ultraviolet (UV), visible (VIS)or infrared (IR) wavelengths) in an example. In some examples, thespectroscopic sensor 142 may include more than a single type ofspectrometer or imaging camera listed herein to enhance sensing anddetection of various features (e.g., carbonized and non-carbonizedtissue, vasculature, and the like).

In some examples, the spectroscopic sensor 142 (also known asspectrometer) may include any of the spectrometers listed herein, andmay additionally rely on imaging capabilities of an endoscope usedduring a therapeutic procedure. For instance, an endoscope may be usedfor visualizing an anatomical feature during a therapeutic procedure(e.g., laser ablation of a tumor). In such cases, the imagingcapabilities of the endoscope may be augmented by the spectroscopicsensor 142. For example, conventional endoscopes may provide narrow bandimaging suitable for enhanced visualization of anatomical features(e.g., lesions, tumors, vasculature, and the like). By combining thespectroscopic sensor 142 with endoscopic imaging (white light and/ornarrow band imaging), may increase detection of tissue properties, suchas level of carbonization, to precisely control the delivery oftherapeutic treatment.

Referring again to FIG. 5, the spectroscopic sensor 142 may beoperatively coupled to a signal detection optical fiber 150. In suchexamples, the signal detection optical fiber 150 may have opticalproperties suitable for transmission of spectroscopic signals from thetissue to the spectroscopic sensor 142. Alternatively, the spectroscopicsensor 142 may be operatively coupled to the first optical fiber 108 ofthe first laser system 102 and/or the second optical fiber 118 of thesecond laser system 104 and thereby detect spectroscopic signals via thefirst optical fiber 108 and/or the second optical fiber 118.

With continued reference to FIGS. 1 and 5, the laser feedback controlsystem 100 includes a laser controller 160 in operative communicationwith each of the spectroscopic sensor 142, the first laser system 102,and optionally the second laser system 104. The laser controller 160 maycontrol one or more laser systems (e.g., the first laser system 102, thesecond laser system 104, and/or any additional laser systems)operatively connected thereto according to one or more controlalgorithms described herein to control the laser outputs from the one ormore laser systems to produce a desired therapeutic effect in the targettissue 122.

The laser controller 160 may include processors, such asmicroprocessors, digital signal processors (DSPs), application specificintegrated circuits (ASICs), field programmable gate arrays (FPGAs), orany other equivalent integrated or discrete logic circuitry, as well asany combinations of such components for performing one or more of thefunctions attributed to the laser controller 160. Optionally, the lasercontroller 160 may be coupled by wired or wireless connections to thespectroscopic sensor 142 and one or more laser systems (e.g., the firstlaser system 102, the second laser system 104, and optional lasersystems not illustrated herein).

The laser controller 160 may communicate with the feedback analyzer 140(e.g., over wired or wireless connections) to receive one or morefeedback signals from the feedback analyzer 140. The laser controller160 may determine one or more properties of the target tissue 122 basedon the feedback signal(s), as will be described further herein. Forinstance, the laser controller 160 may compare the amplitude of thefeedback signals to present minimum and maximum amplitudes, anddetermine a property (e.g., carbonized, coagulated, etc.) of the tissue.

In some examples, the feedback analyzer 140 may continuously monitor thetarget tissue 122 and continuously communicate with the laser controller160 to provide feedback signals. Accordingly, the laser controller 160may continue maintaining the laser systems in one or more states until achange in amplitude of the feedback signal is detected. When a change inamplitude of the spectroscopic signal is detected, the laser controller160 may communicate with the one or more laser systems and change theirstate(s) to deliver a desired therapeutic effect. Alternatively, or inaddition, the laser controller 160 may communicate with an operator(e.g., healthcare professional), and display one or more output(s) viaone or more output system(s) indicative of the feedback signal, and may,optionally, instruct the operator to perform one or more treatmentprocedures with the first laser system and/or the second laser system todeliver a desired therapeutic effect.

In illustrative examples described herein, the laser controller 160 maycontrol the one or more laser systems by changing the state of the lasersystems. According to an aspect, the laser controller 160 mayindependently control each laser system. For instance, the lasercontroller 160 may send a distinct control signal to each laser systemto control each laser system independently of the other laser systems.Alternatively, the laser controller 160 may send a common signal tocontrol one or more laser systems.

In some examples, each of the laser systems may be associated with twodistinct states: a first state wherein the laser system generates alaser output, and a second state where a laser system does not generatea laser output. For instance, the first laser system 102 may have afirst state where a first output 110 (e.g., over the first wavelengthrange) is generated, and a second state where the first output 110 isnot generated. Similarly, the second laser system 104 may have a firststate where a second output 120 (e.g., over the second wavelength range)is generated, and a second state where the second output 120 is notgenerated. In such examples, the laser controller 160 may control theone or more laser system by sending control signals that change thestate of the laser system from the first state to the second state, orfrom the second state to the first state. Further, optionally, eachlaser system may have additional states, for instance, a third statewhere a laser output over different wavelength range is generated.Accordingly, additional control signals may be sent by the lasercontroller 160 to the laser system(s) to change their states from theircurrent state to one or more additional states (e.g., first state tothird state, second state to third state, third state to first state,and third state to second state) to generate laser outputs that providea desired therapeutic effect.

Example Laser System Control Algorithms

FIGS. 6 and 7 are flow diagrams illustrating examples of algorithms forcontrolling one or more laser systems using the laser feedback controlsystem 100 according to some examples as described in this disclosure.In accordance with control algorithm 600 as shown in FIG. 6, at step602, a first signal (e.g., spectroscopic signal) may be detected by thefeedback analyzer 140 (e.g., spectroscopic sensor 142 or imaging sensor144). At step 604, the laser controller 160 may receive the first signalfrom the feedback analyzer 140. The first signal may correspond to afirst property. At step 606 the laser controller 160 may determinewhether the first signal generally equals a first preset value. Forexample, the laser controller 160 may compare the amplitude of the firstsignal to a target value or preset extrema (e.g., maximum or minimumamplitudes) and determine the first property of the target tissue 122.The first property may be indicative of tissue's characteristics afterreceiving a therapeutic treatment (e.g., ablated or carbonized tissue).The laser controller 160 may determine based on the first property(comparison between the first signal and the first preset value) thatthe desired therapeutic effect has been obtained, and may, at step 608send a first control signal to the first laser system 102 to change froma first state of the first laser system 102 to a second state the firstlaser system 102. According to an example, this may result in the firstlaser system 102 no longer generating the first output 110, as a resultof satisfactory delivery of therapeutic effect (e.g., ablation).Alternatively, if at step 606, it is determined that the first signaldoes not generally equal the first preset (not sufficient ablation), thelaser controller may not send any control signals, and the feedbackanalyzer may continue monitoring the first signal.

Optionally, at step 612, the feedback analyzer 140 may receive a secondsignal, distinct from the first signal. The second signal may beindicative of the first property of the target tissue having a secondpreset value. For instance, the amplitude of reflected light from thetissue may be different in the second signal than in the first signal.At optional step 614, the second signal may be received by the lasercontroller 160. At optional step 616, the laser controller 160 maydetermine whether the second signal generally equals the second preset.For instance, the second signal (e.g., a spectroscopic signal or image)may be indicative of the target tissue 122 not being carbonized byabsorption of the first output 110 (e.g., measured signal amplitudebeing less than a preset maximum amplitude of a spectroscopic signal orimage of ablated tissue). In some instances, such a condition may beindicative of inadequate ablation or other unsatisfactory therapeuticeffect, and it may be desirable to continue delivering laser output sothat the tissue can be ablated. Accordingly, at optional step 618, thelaser controller 160 may communicate with the first laser system 102 tosend a second control signal. The second control system may, in anmaintain the first laser system 102 in the first state (e.g., tocontinue delivering the first output 110). Alternatively, if the firstlaser system is in the second state (e.g., off), at optional step 620,the second control signal may change the state of the first laser systemto the first state (e.g., on), for instance, to continue deliveringadditional ablation to the target tissue.

At optional step 620, after the laser controller 160 determinessatisfactory delivery of the therapeutic condition, the laser controller160 may perform additional control operation to deliver additional laseroutputs (e.g., at a different wavelength) to deliver an additionaltherapeutic effect(s).

FIG. 7 illustrates a control algorithm for control of a dual lasersystem. Algorithm 700 may be suitable in instances where the lasercontroller 160 is in operative communication with two or more lasersystems. In some such examples, the first laser system 102 may beconfigured for delivering a first output 110 (e.g., in a firstwavelength range), and the second laser system 104 may be configured fordelivering a second output 120 (e.g., in a second wavelength rangedifferent from the first wavelength range) as described previously.Control algorithm 700 may control the first laser system 102, the secondlaser system 104 and optionally, additional laser systems.

In accordance with control algorithm 700, at step 702, a first signal(e.g., spectroscopic signal or image) may be detected by the feedbackanalyzer 140. At step 704, the laser controller 160 may receive thefirst signal from the feedback analyzer 140. At step 706 the lasercontroller 160 may determine whether the first signal is generally equalto a first preset value (such as within a specified tolerance margin ofthe first preset). For example, the laser controller 160 may compare theamplitude of the first signal to a target value or preset extrema (e.g.,maximum or minimum amplitudes) and determine the first property of thetarget tissue 122. The first property may be indicative of tissue'scharacteristics after receiving a therapeutic treatment (e.g., ablatedor carbonized tissue). The laser controller 160 may determine based onthe first property meeting the target value or preset criteria that thedesired therapeutic effect has been obtained, and may, at step 708 senda first control signal to the first laser system 102 to change from afirst state of the first laser system 102 to a second state the firstlaser system 102. For example, the laser controller 160 may determinethat ablation has been satisfactory based on reflected light from theablated tissue, and send a first control signal to the first lasersystem to turn the first laser system to an OFF state. Alternatively, inillustrative examples, the laser controller 160 may provide an output toan operator (e.g., healthcare professional) to indicate that the desiredtherapeutic effect has been reached, and/or indicate to the operator tochange the state of the first laser system to “OFF” state.

At step 708, the laser controller 160 may also send a fourth signal to asecond laser system 104 to change from a second state of the secondlaser system 104 to a first state of the second laser system 104. Forinstance, the second laser system 104 may be more suitable for ablatingcarbonized tissue. Accordingly, upon detecting that the tissue has beenadequately carbonized (e.g., at step 708), the laser controller 160 may,in some instances, send the first control signal to switch off the firstlaser system 102, and send the fourth control signal to switch on thesecond laser system 104. An example timing diagram of the states of thefirst laser system and the second laser system is shown in FIG. 8.

In some examples, the first control signal and the fourth control signalmay be sent simultaneously. Alternatively, the first control signal andthe fourth control signal may be sent in succession.

Returning to FIG. 7, at optional step 710, the feedback analyzer 140 maydetect a second signal (e.g., spectroscopic signal or image), distinctfrom the first signal. For instance, the second signal may be indicativeof the target tissue 122 not being carbonized by absorption of the firstoutput 110 (e.g., measured signal amplitude being greater than a presetmaximum amplitude of a spectroscopic signal of ablated tissue). In someinstances, such a condition may be indicative of inadequate ablation orother unsatisfactory therapeutic effect, and it may be desirable tocontinue delivering laser output so that the tissue can be ablated. Atoptional step 712, the laser controller may receive the second signal,and at optional step 714, compare the second signal to a second presetvalue. If the second signal is generally equal to the second presetvalue (such as within a specified tolerance margin of the secondpreset), at optional step 716, the laser controller 160 may send thesecond control signal to the first laser system and the third controlsignal to the second laser system. An example timing diagram of thestates of the first laser system and the second laser system is shown inFIG. 8.

The second control signal may, in some examples, change the first lasersystem from the second state (e.g., OFF) to the first state (e.g., ON).Alternatively, if the first laser system is in the first state (e.g.,ON), the second control signal may maintain the first laser system 102in the first state (e.g., to continue delivering the first output 110).Optionally, at step 716, the laser controller 160 may send a thirdcontrol signal to the second laser system 104, thereby changing thesecond laser system 104 from the first state (e.g., ON) of the secondlaser system 104 to the second state (e.g., OFF) of the second lasersystem 104, if the second laser system 104 is in its first state.Alternatively, the third control signal may maintain the second lasersystem 104 in the second state (e.g., OFF) if the second laser system isin the second state.

According to some examples, the first state of each of the first lasersystem 102 and the second laser system 104 may correspond to generationof a first output 110 by the first laser source 106 and a second output120 by a second laser source 116 respectively. Accordingly, the firststate of each of the first laser system 102 and the second laser system104 may represent an “on” state. In some such examples, the second stateof each of the first laser system 102 and the second laser system 104may correspond to an “off” state.

Referring to FIG. 5, the laser feedback control system 100 may includeone or more output systems 170. The one or more output systems 170 maycommunicate with and/or deliver signals to users and/or to other systemssuch as an irrigation suction/pumping system used for a therapeutictreatment, or an optical display controller, or other systems. Theoutput system 170 may include a display 172 in some examples. Thedisplay 172 may be a screen (e.g., a touchscreen), or in thealternative, may simply be a visual indicator (e.g., LED lights of oneor more colors). In additional examples, the output system 170 mayinclude auditory output systems 174 capable of providing auditorysignals (e.g., speakers, an alarm system and the like). The outputsystem(s) 170 may provide one or more outputs (e.g., LED lights of afirst color, a first message on the screen, an alarm sound of a firsttone) to indicate that a desired therapeutic effect has been achieved.The output(s) may be provided, for instance, at step 610, andoptionally, at step 620. In further optional examples, the outputsystem(s) 170 may provide one or more different outputs when desiredtherapeutic effects have not been achieved. For instance, outputsystem(s) 170 may provide one or more outputs (e.g., LED lights of asecond color, a second message on the screen, an alarm sound of a secondtone) to indicate that a desired therapeutic effect has not beenachieved. Such outputs may prompt the operator (a health careprofessional) to take one or more steps (e.g., perform additionaltreatment steps using the one or more laser systems to provideadditional laser outputs).

FIG. 8 illustrates a timing diagram of a dual laser system with a laserfeedback control system 100 according to an example of delivering tissueablation and coagulation by utilizing two optical wavelengths. However,as described previously, the laser feedback control system 100 may beutilized with a single or multiple optical wavelength systems tooptimize the delivery of laser therapy or other types of therapeuticeffects to target tissues 122. The therapeutic effects may be deliveredin any sequence, including simultaneously. Alternatively, thetherapeutic effects may be delivered at different times.

According to an example, laser energy from a first laser system 102 andthe second laser system 104 may be delivered to a target (e.g., tissuesurface), such as continuously in an example. The first and the secondlaser systems may deliver respective laser energy via the same opticalfiber. Alternatively, the first and the second laser systems may deliverrespective laser energy via respective distinct optical fibers. Opticalfeedback signals 810 with amplitude A_(max) are reflected from thetissue surface and may be detected and analyzed by the feedback analyzer140. The first and second laser systems may alternate their respectiveoperating states (e.g., an ON state or an OFF state). As illustrated inFIG. 8, the first laser system 102 may be switched to its first state,or maintained at its first state (e.g., ON) 820A, while the second lasersystem 104 may be switched to or maintained at a second state (e.g.,OFF). The first laser may be used to ablate and carbonize tissue. Duringoperation of the first laser system 102, the first signal may bereceived by the laser controller 160, and may indicate high absorptionby tissue until its amplitude reduces to a threshold level, A_(min). Thewavelength of the output from the first laser system 102 can be in afirst wavelength range in an absorption spectrum of the target, such asa wavelength suitable for effective carbonization of the target tissue.The tissue has high absorption of laser energy. In an example, the firstlaser output is in a UV-VIS or deep infrared wavelength range.

The laser controller 160 may then change the state of the laser systems,such that the first laser system 102 is in the second state (e.g., anOFF), and the second laser system 104 is in the first state (e.g., ON)830A. The output from the second laser system 104 may be highly absorbedby the carbonized tissue so that the carbonized tissue is ablated,effectively removing the carbonization. The wavelength of the outputfrom the second laser system 104 can be in a second wavelength range inan absorption spectrum of the target. The second wavelength range can bedifferent from the first wavelength range of the output from the firstlaser system 102. The wavelength of the output from the second lasersystem 104 may also be suitable for effective coagulation. In anexample, the second laser output is in an infrared wavelength range(e.g., 100-300 nm). Due to decarbonization process the amplitude of thesignal (e.g., second signal) returns close to the initial level,A_(max). The laser controller 160 may accordingly change the state ofthe lasers, such that the first laser system 102 is in the first state(e.g., ON), and the second laser system 104 is in the second state(e.g., OFF). The process may be repeated, such that the first lasersystem 102 and the second laser system 104 are repeatedly switched totheir ON states 820B and 830B respectively in an alternate fashion asillustrated in FIG. 8, until the desired tissue ablation and/orcoagulation is achieved. In some examples, the optical feedback signals810 as discussed herein may be provided to an electrosurgical systemthat can controllably adjust and optimize electrosurgical energydifferent than laser energy.

Example Endoscopic System with Target Identification

FIGS. 9-11 demonstrate how the target composition analysis may beperformed entirely within an endoscope. The target composition analysismay be performed via spectroscopy through the laser fiber andpotentially a camera on the distal tip of a digital endoscope.

FIGS. 9A-9B illustrates an example of an endoscope with a laser fiberinserted. An elongate body portion of an exemplary endoscope 910encompasses various components, including a laser fiber 912, anillumination source 914, and a camera 916. The laser fiber 912 is anexample of the optical pathway 108 of the laser system 102 or the lasersystem 202. The laser fiber 912 may extend along a working channel 913within the elongate body of the endoscope 910. In some examples, thelaser fiber 912 may be separate from the endoscope. For example, thelaser fiber 912 may be fed along a working channel of the endoscopeprior to use, and retrieved from a working channel of the endoscopeafter use.

The illumination source 914 may be a part of a visualization system thatallows an operator to visualize the target structure (e.g., tissue orcalculi structures). Examples of the illumination source can include oneor more LEDs configured to emit light distally away from the distal endof the elongate body of the endoscope to illuminate the field of thetarget structure. In an example, the illumination source 914 may emitwhite light to illuminate the target structure. White light can allowthe practitioner to observe discolorations or other color-based effectson the calculi or on the tissue proximate the distal end of the body ofthe endoscope. In an example, the illumination source 914 may emit bluelight to illuminate the target structure. Blue light can be well-suitedto show thermal tissue spread and thereby detect damage in the tissue.Other colors and/or color bands, such as red, amber, yellow, green, orothers, can also be used.

The camera 916 is a part of the visualization system. The camera 916 isan example of the imaging sensor 244. The camera 916 can capture a videoimage or one or more static images of the illuminated target structureand the surrounding environment. The video image can be in real-time, ornearly real-time with a relatively short latency for processing, so thatthe practitioner can observe the target structure as the practitionermanipulates the endoscope. The camera 916 can include a lens and amulti-pixel sensor located at a focal plane of the lens. The sensor canbe a color sensor, such as a sensor that provides intensity values forred light, green light, and blue light for each pixel in the videoimage. The circuit board can produce a digital video signal representingthe captured video image of the illuminated calculi. The digital videosignal can have a video refresh rate of 10 Hz, 20 Hz, 24 Hz, 25 Hz, 30Hz, 40 Hz, 50 Hz, 60 Hz, or another suitable video refresh rate.

FIGS. 10A-10B illustrate examples of feedback-controlled laser treatmentsystems. In FIG. 10A, a laser treatment system 1000A including anendoscope 910 integrated with a feedback-controlled laser treatmentsystem 1010 that receives camera feedback. The laser treatment system1000A, which is an example of the laser treatment system 100, comprisesthe endoscope 910, the feedback-controlled laser treatment system 1010,a laser source 1020, and a light source 1030. In various examples, aportion or the entirety of the feedback-controlled laser treatmentsystem 1010 may be embedded into the endoscope 910.

The feedback-controlled laser treatment system 1010, which is an exampleof the laser feedback control system 200, includes a spectrometer 1011(an example of the spectroscopic sensor 242), a feedback analyzer 1012(an example of at least a portion of the feedback analyzer 240), and alaser controller 1013 (an example of the laser controller 260). Thelaser source 1020 is an example of the laser system 202, and can becoupled to the laser fiber 912. Fiber integrated laser systems may beused for endoscopic procedures due to their ability to pass laser energythrough a flexible endoscope and to effectively treat hard and softtissue. These laser systems produce a laser output beam in a widewavelength range from UV to IR area (200 nm to 10000 nm). Some fiberintegrated lasers produce an output in a wavelength range that is highlyabsorbed by soft or hard tissue, for example 1900-3000 nm for waterabsorption or 400-520 nm for oxy-hemoglobin and/or deoxy-hemoglobinabsorption. Table 1 above is a summary of IR lasers that emit in thehigh water absorption range 1900-3000 nm.

Some fiber integrated lasers produce an output in a wavelength rangethat is minimally absorbed by the target soft or hard tissue. Thesetypes of lasers provide effective tissue coagulation due to apenetration depth that similar to the diameter of a small capillary 5-10μm. Examples of laser source 1020 may include UV-VIS emittingIn_(X)Ga_(1-X)N semiconductor lasers such as GaN laser with emission at515-520 nm, In_(X)Ga_(1-X)N laser with emission at 370-493 nm,Ga_(X)Al_(1-X)As laser with emission at 750-850 nm, or In_(X)Ga_(1-X)Aslaser with emission at 904-1065 nm, among others.

The light source 1030 may produce an electromagnetic radiation signalthat may be transmitted to the target structure 122 via a first opticalpathway extending along the elongate body of the endoscope. The firstoptical pathway may be located within the working channel 913. In anexample, the first optical pathway may be an optical fiber separate fromthe laser fiber 912. In another example, as illustrated in FIG. 10A, theelectromagnetic radiation signal may be transmitted through the samelaser fiber 912 used for transmitting laser beams. The electromagneticradiation exits the distal end of the first optical pathway and projectsto the target structure and surrounding environment. As illustrated inFIG. 10A, the target structure is within the view of the endoscopiccamera 916, such that in response to the electromagnetic radiationprojecting to the target structure and surrounding environment, theendoscopic camera 916, such as a CCD or CMOS camera, may collect thesignal reflected from target structure 122, produce an imaging signal1050 of the target structure, and deliver the imaging signal to thefeedback-controlled laser treatment system 1010. In some examples,imaging system other than the CCD or CMOS camera, such as laserscanning, can be used for collecting spectroscopic response.

In addition to or in lieu of the feedback signal (e.g., imaging signal)generated and transmitted through the camera system 916, in someexamples, the signal reflected from the target structure mayadditionally or alternatively be collected and transmitted to thefeedback-controlled laser treatment system 1010 through a separate fiberchannel or a laser fiber such as associated with the endoscope 910. FIG.10B illustrates an example of a laser treatment system 1000B includingthe endoscope 910 integrated with the feedback-controlled lasertreatment system 1010 configured to receive spectroscopic sensorfeedback. A reflected spectroscopic signal 1070 (which is an example ofthe feedback signals 130 of FIGS. 1 and 2) may travel back to thefeedback-controlled laser treatment system 1010 through the same opticalpathway, such as the laser fiber 912, that is used for transmitting theelectromagnetic radiation from the light source 1030 to the targetstructure. In another example, the reflected spectroscopic signal 1070may travel to the feedback-controlled laser treatment system 1010through a second optical pathway, such as a separate optical fiberchannel from the first optical fiber transmitting the electromagneticradiation from the light source 1030 to the target structure.

The feedback-controlled laser treatment system 1010 may analyze one ormore feedback signals (e.g., the imaging signal 1050 of the targetstructure or the reflected spectroscopic signal 1070) to determine anoperating state for the laser source 1020. The spectrometer 1011 maygenerate one or more spectroscopic properties from the one or morefeedback signals, such as by using one or more of a FTIR spectrometer, aRaman spectrometer, a UV-VIS spectrometer, a UV-VIS-IR spectrometer, ora fluorescent spectrometer, as discussed above with reference tospectroscopic sensor 242. The feedback analyzer 1012 may be configuredto identify or classify the target structure as one of a plurality ofstructure categories or structure types, such as by using one or more ofthe target detector 246 or the target classifier 248. The lasercontroller 1013 may be configured to determine an operating mode of thelaser system 1020, as similarly discussed above with reference to FIG.2.

The light source 1030 may produce electromagnetic radiation within anoptical range from UV to IR. Table 2 below Error! Reference source notfound. presents examples of light source 1030 for the spectroscopicsystem as applicable to the examples discussed herein.

TABLE 2 Light sources for spectroscopic system Application WavelengthRange Type Color/ VIS/NIR 360-2500 nm Tungsten Halogen DUV 190-400 nmDeuterium UV 215-400 nm Deuterium UV/VIS/NIR 215-2500 nmDeuterium/Halogen reflection/absorption UV/VIS/NIR 200-2500 nmDeuterium/Halogen absorption UV/VIS 200-1000 nm Xenon FTIR 2000-25000 nmSilicon Carbide UV/VIS/IR Multiple narrow LED, Laser Diode Fluorescenceemitting

In some examples, the feedback analyzer 1012 may determine a distance1060 (as shown in FIG. 10A) between the distal end of the laser fiber912 and the target structure 122, or between the distal end of theoptical pathway for receiving and transmitting the reflected signal backto the spectrometer 1011 and the target structure 122. The distance 1060may be calculated using a spectroscopic property, such as a reflectancespectrum, produced by the spectrometer 1011. The laser controller 1013may control the laser source 1020 to deliver laser energy to the targetstructure 122 if the distance 1060 satisfies a condition, such asfalling below a threshold (d_(th)) or within a specified laser firingrange. In an example, if the target structure 122 is identified as anintended treatment structure type (e.g., a specified soft tissue type ora specified calculus type) but the target structure 122 is not withinthe range of the laser (e.g. d>d_(th)), the laser controller 1013 mayproduce a control signal to “lock” the laser source 1020 (i.e.,preventing the laser source 1020 from firing). Information about thedistance 1060 and an indication of the target structure being out of therange of laser (d>d_(th)) may be presented to the practitioner, who maythen adjust the endoscope 910 such as repositioning the distal end ofthe laser fiber 912 to move to closer to the target. The distance 1060,as well as the target structure type, may be monitored and determinedcontinuously and presented to the practitioner. When the target isrecognized as the intended treatment structure type, and is within therange of laser (d<=d_(th)), the laser controller 1013 may produce acontrol signal to “unlock” the laser source 1020, and the laser source1020 may aim and fire at the target structure 122 in accordance with thelaser operating mode (e.g., power setting). Examples of methods forcalculating the distance 1060 from spectroscopic data are discussedbelow, such as with reference to FIGS. 24A-24D.

In some examples, the spectrometer 1011 may be configured to generatethe spectroscopic properties (e.g., reflectance spectra) further usinginformation about geometry and positioning of the optical pathwayconfigured to transmit the electromagnetic radiation from the lightsource to the target. For example, an outer diameter of the laser fiber912 or an outer diameter of a separate optical pathway for transmittingthe spectroscopic signal reflected from the target to the spectrometer1011, or an angle of protrusion of said fiber or pathway from theendoscope 910, may affect the intensity of reflected signal. The outerdiameter and/or the protrusion angle may be measured and provided to thespectrometer 1011 to obtain the reflectance spectra data. The distance1060 between the target structure and the distal end of the fiber, asdiscussed above, may be calculated using the spectra data, the measuredouter diameter of the fiber or optical pathway and its angle ofprotrusion, and/or input signals from the endoscopic image processor.

FIGS. 11A-11B are diagrams illustrating examples of an endoscopic systemfor identifying a target using a diagnostic beam. As illustrated in FIG.11A, an endoscopic system 1100A can include an endoscope 1110, and anoptical fiber 1120A that can be insertable through a working channel1112 of the endoscope 1110. The endoscope 1110 can include, or otherwisebe coupled to via an endoscope port 1114, at least one endoscopicillumination source 1130. The at least one endoscopic illuminationsource 1130 may be controllably provide different amounts ofillumination. The optical fiber 1120A, when inserted through the workingchannel 1112, can be coupled to a non-endoscopic illumination source1140 such as via the endoscope port 1114. The non-endoscopicillumination source 1140 can be different from the at least oneendoscopic illumination source 1130. The non-endoscopic illuminationsource 1140 can emit a diagnostic beam 1142 through the optical fiber1120A and proximate a distal end 1116 of the endoscope 1110. The opticalfiber 1120A can direct the diagnostic beam 1142 at a target 1001. In anexample, the non-endoscopic illumination source 1140 can be a lasersource configured to emanating the diagnostic beam including a laserbeam. In various examples, white light lamps, led light source, orfluoroscopy light sources may be inserted through the working channel ofthe endoscope or inserted through another port such as a laparoscopicport.

The endoscopic system 1100A may include a controller 1150. Thecontroller 1150 may controllably operate the at least one endoscopicillumination source 1130 in different operating modes, including forexample, a first mode having a first amount of illumination and thesecond mode having a second amount of illumination lower than the firstamount. In an example, the controller 1150 may generate such a controlsignal to change the illumination mode (e.g., from the first mode to thesecond mode) in response to a trigger signal. In an example, theendoscope includes an imaging system 1160 that can take an image of thetarget 1001, and the controller 1150 can generate a control signal tothe endoscope to change the illumination mode (e.g., from the first modeto the second mode) in response to a change in brightness or intensityof an image of the target. The first mode is hereinafter referred to ashigh-illumination mode, and the second mode is hereinafter referred toas low-illumination mode. In an example, the high-illumination mode andthe low-illumination mode may be provided by respective differentendoscopic illumination sources, such as a first endoscopic illuminationsource configured to emit illumination light under the high-illuminationmode, and a different second endoscopic illumination source configuredto emit illumination light under the low-illumination mode. Theillumination light can be emitted proximate the distal end 1116 of theendoscope 1110. In an example, the illumination light can travel throughan optical pathway, different than the optical fiber 1120A, within theworking channel 1112. The optical pathway can direct the illuminationlight 1132 at the same target 1001 onto which the diagnostic beam isprojected.

The controller 1150 may generate a control signal to the non-endoscopicillumination source 1140 to emit a diagnostic beam 1142 (e.g., a laserbeam with a lower than therapeutic level of energy) when the at leastone endoscopic illumination source 1130 changes from thehigh-illumination mode to the low-illumination mode. In an example, thelow-illumination mode includes switching off illumination of theendoscope. By dimming the illumination at the target site under thelow-illumination mode, reflection from the target of the diagnostic beamincident on the target can be enhanced, which can help improve targetidentification.

In some examples, the controller 1150 may generate a control signal to adisplay to display an image of the target while the illumination mode isin the second mode, wherein the image is either a prior image or amodified image of a current image of the target. The controller 1150 maydetermine a composition of a target based on the diagnostic beamincident on the target and light from the diagnostic beam beingreflected from the target. In an example, the controller 1150 maydetermine a first composition of a first portion of a calculus target,and to determine a different second composition of a second portion ofthe calculus target. Based on the identified composition of differentportions of the target, the controller 1150 may program a first lasersetting, or generate a recommendation of programming the first lasersetting, to target the first portion of the calculus target. Thecontroller 1150 may further program a second laser setting differentfrom the first laser setting, or generate a recommendation ofprogramming the second laser setting, to target the second portion ofthe calculus target.

In an example, after the non-endoscopic illumination source 1140 hasstopped emanating the diagnostic beam 1142, the controller 1150 maygenerate a control signal to the endoscope to change the illuminationmode from the low-illumination mode back to the high-illumination mode.

FIG. 11B illustrates an example of the endoscopic system 1100B, which isa variant of the endoscopic system 1100A. In this example, thediagnostic beam 1142 can be transmitted through an optical fiber 1120B.Unlike the optical fiber 1120A that is inserted into the working channel1112 of the endoscope 1110, the optical fiber 1120B can be disposed in aseparate from the working channel 1112. In some examples as illustratedin FIG. 11B, the diagnostic beam 1142 may be delivered through asecondary port 1115, such as a laparoscopic port in an example, separatefrom the endoscopic port 1114 used for delivering endoscopicillumination light. The optical fiber 1120B can be positioned such thatthe distal end 116 of the endoscope 1110 and the distal end of theoptical fiber 1120B both aim at the target 1001.

FIGS. 12 and 13A-13B are diagrams illustrating reflectance spectra datafor identifying different types of targets, such as for identifyingcompositions of several different types of kidney stones, via UV-VISspectroscopy, or UV-VIS-IR spectroscopy. The reflectance spectra datawas collected by aiming a UV-VIS spectrometer or UV-VIS-IR spectrometerat each of the images of the five primary types of kidney stonesincluding calcium oxalate stone (Monohydrate), calcium oxalate stone(Dihydrate), calcium phosphate stone, struvite stone, and uric acidstone. In an example, the electromagnetic radiation can include one ormore ultraviolet wavelengths between 10 nm to 400 nm. In anotherexample, as illustrated in FIG. 12, the reflectance spectra used toidentify of different types of targets can be recoded from thespectrometer in a wavelength range 200-1100 nm. Illustrated therein arereflectance spectra of kidney stone compositions, including ammoniummagnesium (AM MAG) phosphate hydrate, calcium (CA) oxalate monohydrate,calcium (CA) oxalate hydrate, calcium (CA) phosphate, and uric acid. Thereflectance spectra of these stone compositions are more discernible atlower wavelength range (e.g., below 400 nm) then at higher wavelengthrange (e.g., above 400). FIG. 13A illustrates a portion of thereflectance spectra shown in FIG. 12 in the 200-400 nm wavelength range,including ammonium magnesium phosphate hydrate spectra 1310, calciumoxalate monohydrate spectra 1320, calcium oxalate hydrate spectra 1330,calcium phosphate spectra 1340, and uric acid spectra 1350. This UVwavelength range is one area where the differences may be identified inthe spectra of the stone images. FIG. 13B illustrates reflectancespectra of various kidney stone compositions in the 400-700 nmwavelength range, including cystine spectra 1360, uric acid spectra1370, and calcium oxalate monohydrate spectra 1380. With the UV-VISspectroscopy or the UV-VIS-IR spectroscopy, it is possible todistinguish between different types of targets, such as different typesof kidney stones.

Since the UV wavelength range is, thus, promising in distinguishingdifferent target compositions, such as kidney stones for example, thereis need for a light source within the system that will allow foranalysis of this region. FIG. 14 shows light peaks 1410, 1420, 1430, and1440 that cover respective sections of the UV wavelength range around250 nm, 280 nm, 310 nm, and 340 nm, respectively. FIG. 15 overlays theselight peaks 1410-1440 with the normalized reflectance spectra of theseveral types of stones from FIGS. 13A-13B. These light peaks 1410-1440demonstrate a potential light source that would allow a spectrometer toanalyze the composition of target in the UV wavelengths.

FIG. 16A illustrates an example of normalized reflectance spectracaptured on a UV-VIS spectrometer from various tissue types, includingcartilage spectra 1610, bone spectra 1620, muscle spectra 1630, fatspectra 1640, and liver tissue spectra 1650. FIG. 16B illustratesanother example of normalized reflectance spectra captured on a UV-VISspectrometer from various soft and hard tissue, including cartilagespectra 1610, bone spectra 1620, muscle spectra 1630, fat spectra 1640,liver tissue spectra 1650, and blood vessel spectra 1660. Thereflectance spectra data shown in FIGS. 16A-16B demonstrate thefeasibility of analyzing the composition of a target from a method thatcould be utilized within the working channel of an endoscope. Similarlyto the spectra captured from the stone images, the UV-VIS region may beused for identifying different types of targets. FIG. 16C illustrates anexample of FTIR spectra of typical stone compositions, and FIG. 16D isin regard to example FTIR spectra of some soft and hard tissuecompositions.

Example Laser treatment System

Features as described herein may be used in relation to a laser systemfor various applications where it may be advantageous to incorporatedifferent types of laser sources. For instance, the features describedherein may be suitable in industrial or medical settings, such asmedical diagnostic, therapeutic and surgical procedures.

Features as described herein may be used with a spectroscopy system,which may be used in combination with a fiber-integrated laser systemand an endoscope.

FIGS. 17-18 illustrate schematic diagrams of a laser treatment system,according to various examples as described in this disclosure. A lasertreatment system may include a laser system configured to deliver laserenergy directed toward a target, and a laser feedback control systemconfigured to be coupled to the laser system. The laser system mayinclude one or more laser modules 1710A-1710N (e.g., solid-state lasermodules) that can emit similar or different wavelength from UV to IR.The number of the integrated laser modules, their output powers,emission ranges, pulse shapes, and pulse trains are selected to balancesystem costs and the performance required to deliver the desired effectsto the targets.

The one or more laser modules 1710A-1710N may be integrated with afiber, and included in a Laser Coupling System. Fiber-integrated lasersystems may be used for endoscopic procedures due to their ability topass laser energy through a flexible endoscope and to effectively treathard and soft tissue. These laser systems produce a laser output beam ina wide wavelength range from UV to IR area (e.g., 200 nm to 10000 nm).Some fiber integrated lasers produce an output in a wavelength rangethat is highly absorbed by soft or hard tissue, for example 1900-3000 nmfor water absorption or 400-520 nm for oxy-hemoglobin and/ordeoxy-hemoglobin absorption. Various IR lasers may be used as the lasersource in endoscopic procedures, such as those describe above withreferenced to Table 1.

The Laser Modules 1710A-1710N may each consist of a number ofsolid-state laser diodes integrated into an optical fiber in order toincrease output power and deliver the emission to the target. Some fiberintegrated lasers produce an output in a wavelength range that isminimally absorbed by the target soft or hard tissue. These types oflasers provide effective tissue coagulation due to a penetration depththat similar to the diameter of a small capillary 5-10 μm. Thefiber-integrated Laser Modules 1710A-1710N as described according tovarious examples in this disclosure have several advantages. In anexample, the light emitting by a Laser Module has a symmetric beamquality, circular and smooth (homogenized) intensity profile. Thecompact cooling arrangements is integrated into a laser module and makecompact the whole system. The fiber-integrated Laser Modules 1710A-1710Ncan be easily combined with another fiber optic components.Additionally, the fiber-integrated Laser Modules 1710A-1710N supportstandard optical fiber connectors that allow the modules to operate wellwith the most optical modules without alignment. Moreover, thefiber-integrated Laser Modules 1710A-1710N can be easily replacedwithout changing the alignment of the Laser Coupling System,

In some examples, a laser Module may produce a laser output inwavelength range that is highly absorbed by some materials such as softor hard tissue, stone, bone, tooth etc., for example 1900-3000 nm forwater absorption or 400-520 nm for oxy-hemoglobin and/ordeoxy-hemoglobin absorption, as illustrated in FIG. 3C. In some examplesa Laser Module may produce a laser output in a wavelength range that islow absorbed by the target, such as soft or hard tissue, stone, bone,tooth etc. This types of laser provide more effective tissue coagulationdue to a penetration depth that similar to the diameter of a smallcapillary (e.g., 5-10 μm), as illustrated in FIG. 3C. Commerciallyavailable solid-state lasers are potential emitting sources for thelaser modules. Examples of laser sources for the Laser Modules mayinclude UV-VIS emitting In_(X)Ga_(1-X)N semiconductor lasers, such asGaN (emission 515-520 nm) or In_(X)Ga_(1-X)N (emission 370-493 nm),GaXAl1-XAs laser (emission 750-850 nm), or InXGa1-XAs laser (emission904-1065 nm). Such laser sources may also be applicable to tissuecoagulation applications.

The laser feedback control system may comprise one or more subsystemsincluding, for example, a spectroscopy system 1720, a feedback analyzer1730, and a laser controller 1740.

Spectroscopy System 1720

The spectroscopy system 1720 may send a control light signal from alight source to a target, such as, but not limited to, a calculi, softor hard tissue, bond, or tooth, or industrial targets, and collectsspectral response data reflected from the target. The response may bedelivered to a spectrometer through a separate fiber, laser fiber, orendoscope system. The spectrometer may send the digital spectral data tothe system feedback analyzer 1730. Examples of light sources for thespectroscopic system that cover an optical range from UV to IR caninclude those described above with reference to Table 2. FIG. 20illustrates a schematic diagram of the Spectroscopic System 1720 withFeedback Analyzer 1730 in an example.

Optical spectroscopy is a powerful method that may be used for easy andrapid analysis of organic and inorganic materials. According to variousexamples described in this disclosure, a spectroscopic light source maybe integrated into a separate fiber channel, a laser fiber or anendoscope system. A light source signal reflected from the target may berapidly collected and delivered to the spectrometer by an imaging systemcontaining a detector such as a CCD or CMOS sensor for example, whichcan be included in a digital endoscope. Other imaging system like laserscanning may also be used for collecting spectroscopic response. Theoptical spectroscopy has several advantages. It can be easily integratedwith a fiber laser delivery system 1701. It is a nondestructivetechnique to detect and analyze material chemical composition, and theanalysis can be performed in real time. The optical spectroscopy can beused to analyze different types of materials including, for example,hard and soft tissue, calculi structures, etc.

Various spectroscopic techniques may be used alone or in combination toanalyze target chemical composition and create the spectroscopicfeedback. Examples of such spectroscopic techniques may include UV-VISreflection spectroscopy, fluorescent spectroscopy, Fourier-TransformInfrared Spectroscopy (FTIR), or Raman spectroscopy, among others. Table2 above presents examples of light sources for the Spectroscopic Systemthat cover an optical area from UV to IR and applicable to an example.Tungsten Halogen light sources are commonly used to do spectroscopicmeasurements in the visible and near IR range. Deuterium light sourcesare known for their stable output and they are used for UV absorption orreflection measurements. The mixes of the Halogen light with theDeuterium light produces a wide spectral range light source providing asmooth spectrum from 200-2500 nm. A Xenon light source is used inapplications where a long lifetime and high output power is needed, suchas in fluorescence measurements. LED and Laser Diodes light sourcesprovide high power at a precise wavelength; they have long lifetime,short warm-up time and high-stability. A spectroscopic light source canbe integrated into a separate fiber channel, laser fiber or endoscopesystem. A light source signal reflected from the target can be rapidlydetected and delivered to the spectrometer though a separate fiberchannel or laser fiber.

Feedback Analyzer 1730

The feedback analyzer 1730 may receive inputs from various sourcesincluding spectroscopic response data from a spectrometer to suggest ordirectly adjust laser system operating parameters. In an example, thefeedback analyzer 1730 may compare the spectroscopic response data to anavailable database library of target composition data. Based on thespectroscopic system feedback, the signal analyzer detects targetmaterial composition, and suggests a laser operating mode (also referredto as a laser setup), such as operating parameters for at least onelaser module, to achieve effective tissue treatments for the identifiedtissue composition. Examples of the operating parameters may include atleast one laser wavelength, pulsed or continuous wave (CW) emissionmode, peak pulse power, pulse energy, pulse rate, pulse shapes, and thesimultaneous or sequenced emission of pulses from at least one lasermodule. Although not explicitly described, sequenced pulses includesbursts of pulses which combine to deliver the selected pulse energy.Pulses as described herein refers generally to the time between startingand stopping a laser emission from a laser module. The intensity of thelaser energy during each pulse may vary to have the shape of anincreasing or decreasing ramp or sinusoidal profile, or any other shapealone or in combination with a sequence of pulses so long as theselected average laser power is maintained. For example, a 2 W averagepower setting with a pulse energy of 1 J occurs at a frequency of 2 Hzif there is only one pulse. However, the energy may also be delivered astwo 0.5 J pulses in quick succession that occurs at a rate of 2 Hz. Eachof those pulses may have similar pulse shapes, or different. TheFeedback Analyzer 1730 utilizes algorithms and input data to directlyadjust or suggest laser operating parameters such as those described inthe example above.

In some examples, the feedback analyzer 1730 may utilize input data tocalculate and control the distance between the distal end of the laserdelivery system 1701 (fiber) and a target based on specially developedalgorithm. In the case of mobile target (e.g., calculi), the FeedbackAnalyzer 1730 may adjust or suggest laser operating parameters thatcreates a suction effect using vapor bubbles in water to pull targetsthat are beyond a predetermined threshold closer to the distal end ofthe fiber. This feature minimizes the effort users need to exert tomaintain an effective treatment distance with mobile targets. Thedistance between the target and the distal end of the fiber may becalculated using spectral data, the known outer diameter of each fiberand its angle of protrusion from the endoscope, and/or input signalsfrom the endoscopic image processor. FIGS. 24A-24D illustrated by way ofexample methods of calculating a distance between the distal end of thelaser delivery system 1701 (fiber) and the target. An dependence of aspectroscopic reflected signal on distance between target and the laserdelivery system 1701 is illustrated in FIGS. 24A-24B. FIG. 24Aillustrates an example of reflected signal intensity at 730 nm measuredat different distances between the tissue and spectroscopic probe distalend. FIG. 24B illustrates an example of reflected signal intensity at450 nm measured at different distances between the tissue andspectroscopic probe distal end. Such dependence is can be determinedusing spectral data and information about Laser Delivery systemgeometry. Analysis of a spectroscopic signal allow quick estimation ofthe distance and delivering this information to the user.

FIG. 24C is an exemplary algorithm of a distance calculation between thefiber and a tissue target. In one example, a spectroscopic system sendsa control light signal from a light source to the target, collectsspectral response data from the target, deliver the response signal tothe spectrometer and send the digital spectral data from thespectrometer to the feedback analyzer. A calibration curve 1000, asshown in FIG. 24C, represents a relationship between a spectroscopicreflected signal intensity (e.g., spectroscopic signal reflected fromthe target structure in response to the electromagnetic radiation) andthe distance 1060 between a distal end of a fiber and a target structureusing the feedback signal reflected from the target structure, such asillustrated in FIGS. 10-11. The calibration curve 1000 may be generatedby measuring the reflected signal intensity at different distancesbetween the tissue and spectroscopic probe distal end when the targetstructure is projected by electromagnetic radiation at a specificwavelength (e.g., 450 nm or 730 nm). By referencing the calibrationcurve, analyses of a spectroscopic signal allow quick estimation of thedistance.

An exemplary process of generating the calibration curve is as follows.First, reference value for each distance may be calculated. Thecalibration curve itself may not be used for identifying the distance,because light reflection intensity depends of the reflectance ofspecimen or so on. One example of reference value to cancel the effectof reflectance of specimen is as follows:

Reference value=dI/dx*1/I   (1)

During an in vivo surgery process, an operator may move the fiber orendoscope with continuous recording of the spectroscopic feedback untilthe reflection spectra of the target tissue composition can be detected.

Referring to FIG. 24C, a first spectrum may be measured at distance x₁where the reflected signal intensity is I₁. At this timing, actual valueof x₁ and curve of reflected signal intensity is unknown. Then, thefiber or endoscope distal end (reflected light detector) may be movedcontinually, and the next reflection light intensity I₂ corresponding todistance x₂ may be measured. x₂ may be close to x₁, such that the curvebetween x₁ and x₂ may be approximated as linear. At this timing, x₁, x₂and curve of reflected signal intensity is unknown. A compared value maybe calculated using I₁, I₂ and delta (x₂−x₁), as follows:

Compared value=delta(I₂ −I ₁)/delta(x ₂ −x ₁)*1/I ₁   (2)

Then, the reference values are searched for one that is identical to thecompared value. If there is only one reference value (x_(r)) found to beidentical to the compared value given in Equation (2), then x_(r) can bedetermined as distance of x₁. If there are two reference values (x_(r1),x_(r2)), then the fiber or endoscope distal end (reflected lightdetector) may be continued to move, and the next reflection lightintensity I₃ corresponding the distance x₃ may be measured. x₃ may beclose to x₂, so that the curve between x₂ and x₃ may be approximated aslinear. At this timing, x₁, x₂, x₃ and curve of reflected signalintensity is unknown. A new compared value can be calculated as followsusing I₁, I₂, I₃, delta (x₂−x₁), and delta (x₃−x₂).

Compared value=delta (I ₂ −I ₂)/delta(x ₃ −x ₂)*1/I ₂   (3)

Then, the reference values are searched for one that is identical tox_(r1)+delta (x₂−x₁) and x_(r2)+delta (x₂−x₁). The references values canbe compared to the compared value given in Equation (3). The distancewhose reference value is more similar to the compared value is estimatedas actual distance.

Referring to FIG. 24D, during in vivo surgery process, an example methodmay comprise moving the fiber or endoscope with continuous recording ofthe spectroscopic feedback until the reflection spectra of the targetcomposition will be detected. With the major case when the spectroscopicdistal end is moving toward the target, the intensity of the detectedreflected light initially will be weak and will be increased withreducing a distance between the target and a fiber end. For example, thefirst spectrum was measured on distance d₁ where the reflected signalintensity is I₁. Continued slightly moving of the fiber or endoscopedistal end toward the target, with continuous collecting the reflectiondata, and the method may measure the next reflection light intensity I₂corresponding the distance d₂. The method may then comprise calculationof the value of reflected signal intensity change slope=delta(I₂−I₁)/delta(d₂−d₁). To make the value of the calculated slopeindependent on the reflected signal intensity the calculated slope maybe normalized. The final formula to calculate the reflected signalintensity change slope at measured distance becomes:

Slope(normalized)=[delta(I₂ −I ₁)/delta(d ₂ −d ₁)]/I _(o)   (4)

where: I_(o)=AVERAGE(I1,I2)

The method may then compare the calculated slope to the one on thecalibration curve in a library to allow estimating the requireddistance. All calculation can be done fast using software.

FIGS. 25A-25B illustrate an impact of distances between the tissue andspectroscopic probe distal end on the spectra of the reflect light fromthe target. FIG. 25A illustrates exemplary normalized UV-VIS reflectionspectra of various soft tissue types, including bladder endothelialspectra 2511, stomach endothelial spectra 2512, stomach smooth musclespectra 2513, under ureter spectra 2514, ureter endothelial 2515, calyxspectra 2516, bladder muscle spectra 2517, and medulla spectra 2518.FIG. 25B illustrates exemplary UV-VIS reflection spectra of a particulartissue recorded at different distances between the tissue andspectroscopic probe distal end, such as from 0 to 0.25 inch. FIG. 25Ashows some examples of animal soft tissue spectra. FIG. 25B presentsexemplary UV-VIS reflection spectra of a tissue recorded at differentdistances between the tissue and spectroscopic probe distal end. In thisexample, the reflected signal intensity at two spectra maximums of 450nm and 730 nm were measured at different distances between the targettissue and spectroscopic probe distal end presented, as discussed abovewith reference to FIGS. 24A-24B.

Laser controller 1740

The laser controller 1740 can be integrated with a Laser CouplingSystem. The Laser Coupling System couples one or more laser modules(e.g., solid-state laser modules) into a fiber. The Laser Controller1740 may be coupled to the Feedback Analyzer 1730, which may send theoptimized signal with the suggested settings directly to the lasercontroller 1740 (automatic mode), or request operator approval to adjustthe laser settings (semi-automatic mode). FIG. 17 is a schematic diagramof a fully automated Laser System. FIG. 18 is a schematic diagram of asemi-automated Laser System where the System requires user approval,such as via a user interface including an input 1850 and a display 1860.In an example, the laser settings may be adjusted within a set range,which in an example maybe predetermined by the user at the start of theprocedure.

In some examples, the Lasers Controller 1740 may combine two or morelaser pulse trains to create a combined laser pulse train. FIG. 19Aillustrates an example where the laser controller 1740 may generate anumber of (e.g., N) laser pulse trains 1910A-1910N, combine the laserpulse trains 1910A-1910N into a combined pulse train 1920, and exposethe target with the combined pulse train at 1930. FIG. 19B is a diagramillustrating an example of an output laser pulse train 1942 combinedfrom the three different laser trains 1941A, 1941B, and 1941C emittingfrom different Laser Modules. As illustrated therein, the laser trains1941A, 1941B, and 1941C may be turned on at different times, and/orturned off at different times, in accordance with the feedback analyzersignal. In the example as illustrated therein, the output combined laserpulse train 1942 may include portions where two or more of the lasertrains 1941A, 1941B, and 1941C overlap in time.

With the combination of the laser modules 1910A-1910N, spectroscopysystem 1720, and the feedback analyzer 1730, the laser feedback system1740 as described herein can continuously identify the composition of atarget through an endoscope and update the laser settings throughout aprocedure.

The main components of the Laser System may be easily customizeddepending on the targeted medical procedure. For example, the LaserController 1740 supports different lasers types and their combination.This allows a wider range of output signal options including power,wavelength, pulse rates, pulse shape and profile, single laser pulsetrains and combined lasers pulse trains. The operating mode of the LaserSystem may be automatically adjusted, or suggested for each desiredoptical effect. The Spectroscopic System collects information about thetarget materials that is useful for diagnostic purposes, and forconfirming that laser parameters are optimal for the target. TheFeedback Analyzer 1730 may automatically optimize operation mode of thelaser system and reduces risk of human mistake.

Internet of Things (IoT) System 1750

In some examples, the laser system may include an optional IoT system1750 that supports storing the spectral database library on a cloud1752, supports quick access to the spectra and optimal setup databaselibrary, and enables communication between the cloud 1752 and FeedbackAnalyzer 1730. The cloud storage of data supports the use of artificialintelligence (AI) techniques to provide input to the Feedback Analyzer1730, and supports immediate access to algorithm and databaseimprovements.

According to various examples described herein, the IoT system 1750 mayinclude a network where the components of the Laser System cancommunicate and interact the others over the Internet. IoT supportsquick access to the spectra database library stored on a cloud 1752 andperforms communication between the cloud 1752 and feedback analyzer1730. In addition, all of the components of the Laser System may beremotely monitored and controlled if need through the network. Anexample of such successful connection is the Internet of Medical Things(also called the Internet of Health Things) is an available applicationof the IoT for medical and health related purposes, which include datacollection and analysis for research, and monitoring.

In various examples, the IoT system 1750 may support access to variouscloud resources including cloud-based detection, recognition, orclassification of a target structure (e.g., calculi structures oranatomical tissue). In some example, a machine learning (ML) engine maybe implemented in the cloud 1752 to provide services of cloud-basedtarget detection, identification, or classification. The ML engine mayinclude a trained ML model (e.g., machine-readable instructionsexecutable on one or more microprocessors). The ML engine may receivetarget spectroscopic data from the Laser system or retrieve targetspectroscope data stored in the cloud 1752, perform target detection,identification, or classification, and generate an output such as alabel representing a tissue type (e.g., normal tissue or cancerouslesion, or tissue at a particular anatomical site) or a calculus type(e.g., kidney, bladder, pancreobiliary, or gallbladder stone having aparticular composition). The target spectroscopic data, among otherclinical data collected from the patient before or during a procedure,may be automatically uploaded to the cloud 1752 at the end of theprocedure or other scheduled time. Alternatively, a system user (e.g., aclinician) may be prompted to upload the data to the cloud 1752. In someexamples, the output may additionally include a probability of thetarget being identified as tissue or calculi, or a probability of thetarget being classified as a particular tissue type or a calculus type.A system user (e.g., a clinician) may use such cloud services to obtainnear real-time information about target tissue or calculi in vivo suchas while performing an endoscopic laser procedure.

In some examples, the ML engine may include a training module configuredto train a ML model using training data such as stored in the cloud1752. The training data may include spectroscopic data associate withtarget information, such as a tag identifying target types (e.g.,calculi types, or tissue types). The training data may include lab databased on spectroscopic analysis of a variety of tissue types and/orcalculi types. Additionally or alternatively, the training data mayinclude clinical data acquired from multiple patients in vitro or invivo. In some examples, patient-identifying information can be removedfrom the patient clinical data (e.g., spectroscopic data) prior to suchdata being used uploaded to the cloud 1752 to train the ML model or toperform target detection, identification, or classification using atrained ML model. The system may associate the de-identified patientclinical data with a tag identifying source of data (e.g., hospital,laser system identification, procedure time). The clinician may analyzeand confirm target type (e.g., calculi or tissue type) during or afterthe procedure, and associate the target type with the de-identifiedpatient clinical data to form the training data. Using the de-identifiedpatient clinical can advantageously increase the robustness of thecloud-based ML model as additional data from a large patient populationcan be included to train the ML model. This may also enhance theperformance of the ML model to recognize rare calculi types as thespectroscopic data from rare calculi types are difficult to obtainclinically or from a lab.

Various ML model architectures and algorithms may be used, such asdecision trees, neural networks, deep-learning networks, support vectormachines, etc. In some examples, the training of the ML model may beperformed continuously or periodically, or in near real time asadditional spectroscopic data is made available. The training involvesalgorithmically adjusting one or more ML model parameters, until the MLmodel being trained satisfies a specified training convergencecriterion. The resultant trained ML model may be used in cloud-basedtarget detection, recognition, or classification. With a ML modeltrained by exploiting large volume of data stored in the cloud 1752 andadditional data constantly or periodically added thereto, the ML basedtarget recognition with cloud connection as described herein may improvethe accuracy and robustness of in vivo target detection, recognition,and classification.

Example Endoscopic Laser System

FIGS. 21A-21D illustrate examples of an endoscopic laser system 2100Aand 2100B comprising an endoscope 2110 with an integrated multi-fiberaccessory, and a surgical laser system comprising thefeedback-controlled laser treatment system 1010 and the laser source1020, as illustrated in FIG. 10A. Alternatively, a spectroscopicresponse may be collected and delivered to the spectrometer by animaging system containing a detector such as a CCD or CMOS sensor.Target composition analysis may be performed via spectroscopy throughone or more of the cores of the multi-fiber accessory while illuminatingthe target with a light source transmitted through one or more of theother cores of the multi-fiber accessory.

As illustrated in FIG. 21A, the endoscopic laser system 2100A includes amulti-fiber accessory that includes an optical pathway 2116 used fortransmitting the spectroscopic signal back to the spectrometer 1011, aswell as for delivering surgical laser energy from the laser source 1020to the target structure. In an example, the optical pathway 2116includes an optical fiber embedded within and extending along anelongate body of the endoscope 2110. In another example, the opticalpathway 2116 includes two or more optical fibers extending along anelongate body of the endoscope 2110. The laser controller 1013 maycontrol the timing of the laser firing such that the transmission ofspectroscopic signal and delivery of laser energy occur at differenttimes or simultaneously.

The multi-fiber accessory may include two or more light source fibers2114 embedded into and extending along an elongate body of the endoscope2110. By way of example and not limitation, FIG. 21C illustrates aradial cross-sectional view of the elongate body of the endoscope 2110,where a number of light source fibers 2114 and the optical pathway 2116are longitudinally positioned within the elongate body of the endoscope,and the light source fibers 2114 are radially distributed surround theoptical pathway 2116, such as along a circumference with respect to theoptical pathway 2116 on the radial cross-section of the elongate body ofthe endoscope. In the example as shown in FIG. 21C, the optical pathway2116 may be located at substantially the central longitudinal axis ofthe elongate body of the endoscope 2110. By way of example and notlimitation, six light source fibers may be positioned around the opticalpathway 2116, as shown in FIG. 21C. Other number of light source fibers,and/or other positions of the light source fibers relative to theoptical pathway 2116, may be used. For example, FIG. 21D illustrates twolight source fibers 2114 radially positioned at opposite sides of theoptical pathway 2116. The light source fibers 2114 may be coupled to thelight source 1030. Alternatively, the light source fibers 2114 may becoupled to the illumination source 914 as shown in FIG. 9A-9B. Lightfrom the endoscope light source, either the illumination source 914(e.g., one or more LEDs) or the remote light source 1030 such asexternal to the endoscope, may serve the functions of illuminating thetarget and producing spectroscopic signal reflected from the targetsurface which may be collected for spectroscopic analysis. The feedbackanalyzer 1012 may determine the distance 1060 between the distal end ofthe endoscope 2110 and the target structure 122, as similarly shown inFIGS. 10-11.

FIG. 21B illustrates an endoscopic laser system 2100B that includes amulti-fiber accessory. Instead of delivering laser energy through theoptical pathway 2116, a separate laser fiber 2120 may be used fordelivering surgical laser energy from the laser source 1020 to thetarget structure. The optical pathway 2116 is used as a dedicatedspectroscopy signal fiber for transmitting the spectroscopic signal backto the spectrometer 1011.

FIGS. 22 and 23A-23B illustrate examples of the multi-fiber system thatmay be used in a spectroscopic fiber delivery system, such as thatdiscussed above with reference to FIGS. 21A-21D. In the example asillustrated in FIG. 22, a multi-fiber system 2200 includes a first fiber2210 coupled to the light source and configured to direct illuminationlight at the target, and a separate second fiber 2220 coupled to thespectrometer and configured to transmit the reflected signal (e.g.,light reflected from the target) indicative of spectroscopic propertiesof the target to the spectrometer.

FIGS. 23A-23B are diagrams of an exemplary multi-fiber accessory withsource light input and spectroscopy feedback signal. As shown in FIG.23A, a multi-fiber accessory 2300A may include a distal portion 2310, atransition section 2320A, and a proximal portion 2330A. The distalportion 2310 includes a shaft that can be sized and shaped to enclosethe first and second fiber 2210 and 2220, and a transition section 2320Aproximal to the distal portion 2310. The first fiber 2210 and secondfiber 2220 may be embedded in and extend along a longitudinal shaft ofthe distal portion 2310. The shaft can be sized and shaped to extendthrough a working channel of an endoscope. In some examples, the firstfiber 2210 may include two or more optical fibers each coupled to thelight source, and/or the second fiber 2220 may include one or moreoptical fibers. In some examples, as illustrated in FIGS. 21C-21D, thesecond fiber 2220 can be radially distributed surrounding the firstoptical fibers 2210. In an example, at least one of the second opticalfibers 2220 can extend along a substantially central longitudinal axisof the shaft. The two or more first optical fibers 2210 can be radiallypositioned at opposite sides of the second optical fiber 2220 extendingalong the central longitudinal axis of the shaft.

The proximal portion 2330A comprises a first connector 2332 configuredto be connected to the light source, and a second connector 2334configured to be connected to a spectrometer. The transition section2320A interconnects the distal portion 2310 and the proximal portion2330A, and can be configured to couple the first connector 2332 to thefirst fiber 2210 and the second connector 2334 to the second fiber 2220.As such, the transition section 2320A provides a transition of theoptical fibers 2210 and 2220 from the respective first and secondconnectors 2332 and 2334 into the single shaft.

The shaft can include an insertable distal end 2312 extended distallyfrom the distal portion 2310. The insertable distal end 2312 can beconfigured to be inserted into a patient. The proximal portion 2300A canbe associated with (e.g., included within) a handle for a user tooperate the multi-fiber accessory 2300A. In an example, at least aportion of the multi-fiber accessory 2300A (e.g., one or more of thedistal portion 2310, the transition section 2320A, or the proximalportion 2330A) can be included in or insertable into a working channelof an endoscope.

FIG. 23B illustrates another example of multi-fiber accessory 2300B,which is a variant of the multi-fiber accessory 2300A. In the exampleillustrated in FIG. 23B, the proximal portion 2330B may further includea third connector 2336 configured to couple a laser source to one of theoptical fibers 2210 or 2220. Similar to FIG. 23A, a transition section2320B interconnects the distal portion 2310 and the proximal portion2330B. Laser energy generated from the laser source may be transmittedfrom the proximal portion 2330B to the distal portion 2310, through oneof the optical fibers 2210 or 2220, and delivered to a target treatmentsite via the insertable distal end 2312. In some examples, themulti-fiber accessory 2300B may further include a laser fiber differentfrom the optical fibers 2210 or 2220. The laser fiber may be positionedin the working channel of the endoscope, such as within the shaft. Laserenergy generated from the laser source may be transmitted to the distalportion 2310 through the laser fiber.

Example Applications of the Laser System

The Laser System as described in accordance with various examples inthis document can be used in many applications such as endoscopic hardor soft tissue surgery to improve the effectiveness of ablation,coagulation, vaporization, or other laser effects.

One application of the Laser System for tissue surgery application iswith regard to using the laser system to provide effective tissueablation and coagulation, instead of using two different foot pedals asis often done on commercial devices such as lasers and plasma devices.An example system utilizes two or more solid-state Laser Modulesemitting at two different wavelengths coupled through the fibers intoLaser Controller, and a UV-VIS reflection Spectroscopic System thatdeliver spectral signals to the Feedback Analyzer that suggestsalternate settings to a user before being adjusted.

In one examples, two Laser Modules may be provided, including a firstlaser module that can emit at a high tissue absorption opticalwavelength for more efficient ablation/carbonation processes, and asecond laser module that can emit at a lower tissue absorption opticalwavelength for more efficient coagulation such as due to a penetrationdepth that similar to the diameter of a small capillary. Examples of thefirst laser module may include a UV-VIS emitting InXGa1-XN semiconductorlaser: GaN—emission 515-520 nm; InXGa1-XN—emission 370-493 nm or the IRlaser that emit in the high water absorption range, 1900-3000 nm andthat summarized in Table 1. Examples of the second Laser Module mayinclude GaXAl1-XAs with emission 750-850 nm, or InXGa1-XAs with emission904-1065 nm. Both first and second Laser Modules may be coupled into theLaser Controller with laser coupling system.

A spectroscopic light source may be integrated into a separate fiberchannel, laser fiber or endoscope system. A spectroscopic light sourcesignal reflected from the target may be rapidly detected and deliveredto the spectrometer though a separate fiber channel or laser fiber.Alternatively, the Spectroscopy System could collect spectroscopicsignals from an imaging system containing a detector such as a CCD orCMOS sensor. Based on the Spectroscopic system feedback, the SignalAnalyzer may detect target material composition and suggest first orsecond Laser Modules setup to achieve effective tissue treatments, anddeliver signals to an output system used to provide suggested setupinformation to the user.

This example allows for tissue ablation and coagulation by utilizing twoor more laser pulses with optical wavelengths controlled by a FeedbackAnalyzer system. However, feedback control may be utilized with a singleor multiple optical wavelength systems to optimize the simultaneousdelivery of specific effects to targets. These effects may besimultaneous only from the perspective of the user; features asdescribed herein are not limited to delivering wavelengths at exactlythe same time.

An example time operating chart of this laser with spectroscopicfeedback presented in FIG. 8. As described therein, optical feedbacksignals with amplitude A_(max) are continuously delivered to andreflected from the target surface and are detected and analyzed by thesignal analyzer. Then the user may turn ON the first laser, or keeps thefirst laser ON after selecting to ablate soft tissue, while the secondlaser is OFF. During operation of the first laser, the optical feedbacksignal is highly absorbed by carbonized tissue until its amplitudereduces to a threshold level, A_(min). The signal analyzer then changesthe state of the lasers such that the first laser is turned OFF and thesecond laser is turned ON. The second laser is highly absorbed bycarbonized tissue; so the carbonized tissue is ablated, effectivelyremoving the carbonization. The wavelength of the second laser alsoprovides effective coagulation. Due to the decarbonization process, theamplitude of the optical feedback pulses returns close to the initiallevel, A_(max). When this occurs, the signal analyzer changes the stateof the lasers back to the first laser being turned ON and the secondlaser being turned OFF. The above process can be repeated until therequired amount of tissue ablation and coagulation is achieved.

Another application of the Laser System is with regard to efficientlaser lithotripsy process to fragment a kidney or bladder stone in apatient. The application relates to a process using multi wavelengthlasers energy having a wavelength with less absorption by the target toheat a target first and then a stronger absorption wavelength tofragment the target, such as a kidney stone for example. During laserlithotripsy, the kidney or bladder stone fragmentation can occur due toa photothermal effect. High laser energy can be absorbed by the stone,thus causing a rapid temperature rise above the threshold for chemicalbreakdown resulting in its decomposition and fragmentation. In oneexample, a laser lithotripsy can include a two-stage process. The firststage is a pre-heating stage, where a stone is heated using laser energyof a first wavelength that causes lower laser energy absorption by thestone. A subsequent second stage involves an application of laser energywith a second wavelength, which causes a stronger laser energyabsorption by the stone than the first wavelength. Such a multistepprocess allows better controlling vapor bubble creation and reducingstrength of generated shock waves over the fragmentation process(reduces stone retropulsion effect).

In an example, the Laser System utilizes two or more solid-state LaserModules emitting at two different wavelengths coupled through the fibersinto Laser Controller, and a Spectroscopic System that deliver spectralsignals to the Feedback Analyzer that suggests alternate settings to auser before being adjusted. A first Laser Module can emit at a lowerstone/water absorption optical wavelength for efficient pre-heating; anda second Laser Module can emit at a high stone/water absorption opticalwavelength for more efficient stone fragmentation. The first LaserModule in this application may produce an output at a lower stone orwater absorption wavelength. This laser provides effective and uniformstone pre-heating. Examples of the first laser source for the firstLaser Module may include GaXAl1-XAs with emission 750-850 nm, orInXGa1-XAs with emission 904-1065 nm. Examples of the second lasersource may include a UV-VIS laser emitting InXGa1-XN semiconductorlaser, such as GaN laser with emission 515-520 nm, or InXGa1-XN laserwith emission 370-493 nm, or the IR laser that emit in the high waterand stone absorption range, 1900-3000 nm, and that summarized in Table1.

Both first and second Laser Modules may be coupled into the LaserController with laser coupling system. A spectroscopic light source maybe integrated into a separate fiber channel, laser fiber or endoscopesystem. A spectroscopic light source signal reflected from the targetmay be rapidly detected and delivered to the spectrometer though aseparate fiber channel or laser fiber. Alternatively, the SpectroscopySystem may collect spectroscopic signals from an imaging systemcontaining a detector such as a CCD or CMOS sensor.

Based on the Spectroscopic system feedback, the Signal Analyzer maydetect target material composition and suggest first or second LaserModules setup to achieve effective multistep stone treatments processand delivers signals to an output system used to provide suggested setupinformation to the user. The Laser System may simultaneously delivereffective stone preheating and fragmentation by utilizing two or morelaser pulses from Laser Modules with optical wavelengths controlled by aFeedback Analyzer system. However, feedback control may be utilized witha single or multiple optical wavelength systems to optimize thesimultaneous delivery of specific effects to target stone composition.

Yet another application of the Laser System is with regard to a processto perform ablation of hard tissue, for example teeth, bone etc., wherehigh laser output power is required. The effectiveness of soft tissuelaser surgery based on the low-temperature water vaporization at 100°C., however, a hard tissue cutting process require very high ablationtemperatures, as high as 5,000° C. To deliver enhanced output power theLaser System may couple larger number of Laser Modules to increase anintegrated output power to the level that enough to treat the target.The following lasers may be used as emitting sources: UV-VIS emittingInXGa1-XN semiconductor laser: GaN—emission 515-520 nm;InXGa1-XN—emission 370-493 nm or the IR laser 1900-3000 nm and thatsummarized in Table 1. The laser sources for the Laser Modulesapplicable to this example may include, for example, GaXAl1-XAs laserwith emission 750-850 nm, or InXGa1-XAs laser with emission 904-1065 nm.

The Laser Modules may be integrated into the Laser Controller with lasercoupling system. To archive the require high power the large number of aLaser Modules can be coupled into the System. A spectroscopic lightsource may be integrated into a separate fiber channel, laser fiber orendoscope system. A spectroscopic light source signal reflected from thetarget can be rapidly detected and delivered to the spectrometer thougha separate fiber channel or laser fiber. Alternatively, the SpectroscopySystem could collect spectroscopic signals from an imaging systemcontaining a detector such as a CCD or CMOS sensor.

Based on the Spectroscopic System feedback the Signal Analyzer maydetect target material composition and suggest Laser Modules setup andnumber of Laser Modules to achieve the required output power, effectivemultistep treatments process, and deliver signals to an output systemused to provide suggested setup information to the user. The LaserSystem may simultaneously deliver required high laser output power byincreasing number of the Laser Modules involved into the treatmentprocess utilizing two or more laser pulses with optical wavelengthscontrolled by a Feedback Analyzer system. The feedback control may beutilized with a single or multiple optical wavelength systems tooptimize the simultaneous delivery of specific effects to target stonecomposition. These effects may be simultaneous only from the perspectiveof the user; but is not limited to delivering wavelengths at exactly thesame time.

Features as described herein may be used to provide a method to identifythe composition of a target. The target may, in some instances be amedical target, such as soft and hard tissue in vivo through the use ofa surgical accessory. This accessory may be used endoscopically orlaproscopically. The accessory may consist of a single device containingmultiple optical fibers with the intention that at least one fibersupplies a source illumination and at least one fiber to guide reflectedlight to a spectrometer. This allows a user to continuously monitor acomposition of tissue or a target with or without the use of directendoscopic visualization throughout a procedure. This also has theability to be used in combination with a laser system where theaccessory may send feedback to the laser system to adjust the settingsbased on the composition of the tissue or target. This feature willallow for the instant adjustment of laser settings within a set range ofthe original laser setting selected by the user. Features as describedherein may be used with a spectroscopy system, which may be used with anoptical fiber integrated laser system. A spectroscopic light source maybe transmitted through at least one of the fibers in the multi-fiberaccessory. A light source signal reflected from the target may berapidly collected and delivered to the spectrometer via an additionalfiber in the multi-fiber.

An example method may utilize spectroscopic input data to calculate andcontrol the distance between a distal end of laser delivery system 1701(such as a fiber) and a tissue or target based on an algorithm. Themethod may be applied to both soft and hard tissue types for in vivosurgery process. The distance between the target and the distal end ofthe fiber may be calculated based on analyses of spectral data. Outerdiameter of each fiber and its angle of protrusion from the endoscopeaffects the intensity of reflected light; that is measured to obtainspectral data. With features as described herein, a distance may becalculated without sequentially illuminating by the lights withdifferent numerical aperture values.

In the case of mobile calculi, the method may control the distance andmay adjust or suggest laser-operating parameters that creates a suctioneffect using vapor bubbles in water to pull targets that are beyond apredetermined threshold closer to the distal end of the fiber. Thisfeature minimizes the effort users need to exert to maintain aneffective treatment distance with mobile targets.

The UV-VIS-IR reflection spectroscopy in accordance with variousexamples discussed in this document can be used alone or in combinationwith other spectroscopic techniques to create the spectroscopic feedbackincluding analyzes of material chemical composition and measurereflected light intensity during in vivo diagnostic or therapeuticprocedure. The reflected light may yield the same information as the eyeor color image made by high-resolution camera, but it does morequantitatively and objectively. The reflection spectroscopy offersinformation about the material since light reflection and absorptiondepends on its chemical composition and surface properties. It is alsopossible using this technique to get unique information about bothsurface and bulk properties of the sample.

Yet another application of the Laser System is with regard to a processto identifying target type, such as determining composition of a calculitarget during laser lithotripsy. According to some examples discussedherein, an endoscope system has a light source, and the light sourceprovides an illumination light to the target in a human body thorough alight guide of the endoscope. A physician uses the laser system forbreaking stones under the illumination light from the endoscope system.This situation may cause some trouble if the laser system is used fordetecting stone composition. The light reflected from the stones is weakand, on the other hand, the illumination light from the endoscope systemis strong. Therefore, it may be hard to analyze the composition ofstones under illuminating by the endoscope system.

FIG. 26 illustrates an example of an endoscope system 2600 configure toidentify a target (e.g., to identify composition of a calculi target)using a diagnostic beam such as a laser beam. The system 2600 mayinclude a controller 2650 than can control both of an endoscopic lightsource 2630 and a laser generator module 2640. The controller 2650 maydetect the input of a command to activate the stone compositiondetecting mode by the physician through the laser system. The controller2650 may then send a command to the endoscopic light source 2630 to stopilluminating, or switch from a high-illumination mode to alow-illumination mode where a reduced amount of illumination isprojected onto the target for a certain period. During suchlow-illumination or no-illumination period, the laser system 2640 mayemit a laser beam to the target and receive the reflected light from thestone. The detector 2660 may perform target identification using thereflected light. By dimming the illumination at the target site underthe low-illumination mode (or turning off the illumination), reflectionfrom the target of the laser beam incident on the target can beenhanced, which can help improve target identification.

Once the detector 2660 determines that the target identification iscompleted, the detector 2660 may send a termination command to thecontroller 2650. The controller 2650 may then send a command tore-illuminate the target, or switch from the low-illumination back to ahigh-illumination mode. In one example, when the endoscopic light source2630 receives the command to stop illuminating or switching from thehigh-illumination mode to the low-illumination mode, an image processor2670 in the endoscope system 2600 may capture a still image of thetarget, and display the still image on the monitor of the endoscopesystem during the time period. Variations of the endoscope system 2600for identifying a target have been contemplated, such as those discussedabove with reference to FIGS. 11A-11B.

FIG. 27 illustrates a graph 2700 of a sequence of laser pulses havingdifferent pulsed energy or power levels, such as can include a firstpulse train 2710 and a second pulse train 2720. Pulses in the secondpulse train 2720 have higher energy or power levels than the pulses ofthe first pulse train 2710. The first pulse train 2710 and the secondpulse train 2720 may be generated by respective laser sources, and eachemitted from a distal end of an endoscope in forms of respective laserbeams. The first pulse train 2710 may be generated substantiallyconstantly in time, such as over a specific time period (e.g.,controlled by a user). The second pulse train 2720 may be generatedintermittently in time, such as over the specific time period duringwhich the first pulse train 2710 is delivered. For example, the secondpulse train 2720 may be delivered between two pulses of the first pulsetrain 2710, or between two trains of first pulse train 2710. In theexample as shown in FIG. 27, pulses in the first pulse train 2710 have aconstant energy or power level, and the second pulse train 2720 includesonly one pulse with a higher energy or power level than the first pulsetrain 2710. In some examples, the second pulse train 2720 may includetwo or more pulses each having a higher energy or power level than thefirst pulse train 2710.

The sequence of laser pulses as shown in FIG. 27 may be used by a laserlithotripsy system to provide cracking and fragmentation of a calculistructure, such as a kidney for example. As illustrated in FIG. 27, thesequence represents time in the X-direction of the graph, but is alsoannotated with locations “A” and “B” on the stone or other target. Thesequence of the laser pulses thus represents a spatiotemporal pattern oflaser pulses with different pulsed energy or power levels. In thisexample, location “A” is at or near the center of the stone or othertarget, and location “B” is at or near a periphery of the stone or othertarget. The laser pulses issued between locations “A” and “B” illustratepulses that are issued as the laser fiber 140 is being translated fromthe location “A” to the location “B”, or as the laser fiber 140 is beingtranslated from the location “B” to the location “A”, such as caninclude using the actuator. The first pulse train 2710 can be selectedto induce a crack in the target stone without fragmenting the targetstone. Thus, in FIG. 27, such first pulse train 2710 can be issuedbeginning at location “A” toward the center of the stone, thenproceeding toward location “B” toward a periphery of the stone, and thenreturning toward location “A” at the center of the stone, at which timea higher energy pulse 2720 can be delivered in a first attempt tofragment the target stone. If such fragmenting by the higher energypulse 2720 is not successful, then further first pulse train 2710 can bedelivered proceeding from locations toward the center of the stonetoward a location “B” toward the periphery of the stone, and thenreturning toward location “A” at the center of the stone, at which timeanother higher energy pulse 2720 can be delivered in a second attempt tofragment the target stone. Further iterations are also possible. Thesame or a different location “B” toward the periphery of the stone canbe used for the various iterations, with different locations “B” indifferent iterations producing multiple cracks along such pathways fromlocation “A” to such different peripheral location “B”. It may bepreferred to use the higher energy pulse 2720 only toward the center ofthe stone, such as to minimize the effect of the second pulse train 2720on nearby tissue.

In some examples, the sequence of laser pulses having different pulsedenergy or power levels as shown in FIG. 27 may be used by an endoscopicsystem that provides hemostasis or coagulation at a target site. In anexample, the first pulse train 2710 and the second pulse train 2720 maybe delivered in a spatiotemporal pattern, such as an alternating fashionin time for example, to the target site to facilitate an efficienthemostasis or coagulation process.

The pulses with different energy or power levels, such as the firstpulse train 2710 and the second pulse train 2720, may be controllablyactivated via an actuator operable by a user, such as a button or a footpedal. For example, the user may use a first activation pattern (e.g., asingle press of the button or the foot pedal) to activate delivery ofthe first pulse train 2710, and use a second activation pattern (e.g., adouble press of the button or the foot pedal) to activate delivery ofthe second pulse train 2720. In an example, the first pulse train 2710and the second pulse train 2720 may be controlled via respectiveseparate actuators. Additionally or alternatively, the first pulse train2710 and the second pulse train 2720, may be controllably activatedautomatically, such as based on a feedback signal from the target. Forexample, a spectrometer may collect spectroscopic data of the target,and a feedback analyzer may analyze the spectroscopic data to identifycompositions of different portions of a calculi structure. Based atleast on such identification, different energy pulses, such as the firstpulse train 2710 or the second pulse train 2720, may be delivered todifferent portions of the target with respectively identifiedcompositions.

FIG. 28 illustrates generally a block diagram of an example machine 2800upon which any one or more of the techniques (e.g., methodologies)discussed herein may perform. Portions of this description may apply tothe computing framework of various portions of the laser treatmentsystem in accordance with examples as discussed in this document.

In alternative embodiments, the machine 2800 may operate as a standalonedevice or may be connected (e.g., networked) to other machines. In anetworked deployment, the machine 2800 may operate in the capacity of aserver machine, a client machine, or both in server-client networkenvironments. In an example, the machine 2800 may act as a peer machinein peer-to-peer (P2P) (or other distributed) network environment. Themachine 2800 may be a personal computer (PC), a tablet PC, a set-top box(STB), a personal digital assistant (PDA), a mobile telephone, a webappliance, a network router, switch or bridge, or any machine capable ofexecuting instructions (sequential or otherwise) that specify actions tobe taken by that machine. Further, while only a single machine isillustrated, the term “machine” shall also be taken to include anycollection of machines that individually or jointly execute a set (ormultiple sets) of instructions to perform any one or more of themethodologies discussed herein, such as cloud computing, software as aservice (SaaS), other computer cluster configurations.

Examples, as described herein, may include, or may operate by, logic ora number of components, or mechanisms. Circuit sets are a collection ofcircuits implemented in tangible entities that include hardware (e.g.,simple circuits, gates, logic, etc.). Circuit set membership may beflexible over time and underlying hardware variability. Circuit setsinclude members that may, alone or in combination, perform specifiedoperations when operating. In an example, hardware of the circuit setmay be immutably designed to carry out a specific operation (e.g.,hardwired). In an example, the hardware of the circuit set may includevariably connected physical components (e.g., execution units,transistors, simple circuits, etc.) including a computer readable mediumphysically modified (e.g., magnetically, electrically, movable placementof invariant massed particles, etc.) to encode instructions of thespecific operation. In connecting the physical components, theunderlying electrical properties of a hardware constituent are changed,for example, from an insulator to a conductor or vice versa. Theinstructions enable embedded hardware (e.g., the execution units or aloading mechanism) to create members of the circuit set in hardware viathe variable connections to carry out portions of the specific operationwhen in operation. Accordingly, the computer readable medium iscommunicatively coupled to the other components of the circuit setmember when the device is operating. In an example, any of the physicalcomponents may be used in more than one member of more than one circuitset. For example, under operation, execution units may be used in afirst circuit of a first circuit set at one point in time and reused bya second circuit in the first circuit set, or by a third circuit in asecond circuit set at a different time.

Machine (e.g., computer system) 2800 may include a hardware processor2802 (e.g., a central processing unit (CPU), a graphics processing unit(GPU), a hardware processor core, or any combination thereof), a mainmemory 2804 and a static memory 2806, some or all of which maycommunicate with each other via an interlink (e.g., bus) 2808. Themachine 2800 may further include a display unit 2810 (e.g., a rasterdisplay, vector display, holographic display, etc.), an alphanumericinput device 2812 (e.g., a keyboard), and a user interface (UI)navigation device 2814 (e.g., a mouse). In an example, the display unit2810, input device 2812 and UI navigation device 2814 may be a touchscreen display. The machine 2800 may additionally include a storagedevice (e.g., drive unit) 2816, a signal generation device 2818 (e.g., aspeaker), a network interface device 2820, and one or more sensors 2821,such as a global positioning system (GPS) sensor, compass,accelerometer, or other sensors. The machine 2800 may include an outputcontroller 2828, such as a serial (e.g., universal serial bus (USB),parallel, or other wired or wireless (e.g., infrared (IR), near fieldcommunication (NFC), etc.) connection to communicate or control one ormore peripheral devices (e.g., a printer, card reader, etc.).

The storage device 2816 may include a machine readable medium 2822 onwhich is stored one or more sets of data structures or instructions 2824(e.g., software) embodying or utilized by any one or more of thetechniques or functions described herein. The instructions 2824 may alsoreside, completely or at least partially, within the main memory 2804,within static memory 2806, or within the hardware processor 2802 duringexecution thereof by the machine 2800. In an example, one or anycombination of the hardware processor 2802, the main memory 2804, thestatic memory 2806, or the storage device 2816 may constitute machinereadable media.

While the machine-readable medium 2822 is illustrated as a singlemedium, the term “machine readable medium” may include a single mediumor multiple media (e.g., a centralized or distributed database, and/orassociated caches and servers) configured to store the one or moreinstructions 2824.

The term “machine readable medium” may include any medium that iscapable of storing, encoding, or carrying instructions for execution bythe machine 2800 and that cause the machine 2800 to perform any one ormore of the techniques of the present disclosure, or that is capable ofstoring, encoding or carrying data structures used by or associated withsuch instructions. Non-limiting machine-readable medium examples mayinclude solid-state memories, and optical and magnetic media. In anexample, a massed machine-readable medium comprises a machine readablemedium with a plurality of particles having invariant (e.g., rest) mass.Accordingly, massed machine-readable media are not transitorypropagating signals. Specific examples of massed machine-readable mediamay include: non-volatile memory, such as semiconductor memory devices(e.g., Electrically Programmable Read-Only Memory (EPROM), ElectricallyErasable Programmable Read-Only Memory (EPSOM)) and flash memorydevices; magnetic disks, such as internal hard disks and removabledisks; magneto-optical disks; and CD-ROM and DVD-ROM disks.

The instructions 2824 may further be transmitted or received over acommunication network 2826 using a transmission medium via the networkinterface device 2820 utilizing any one of a number of transferprotocols (e.g., frame relay, internet protocol (IP), transmissioncontrol protocol (TCP), user datagram protocol (UDP), hypertext transferprotocol (HTTP), etc.). Example communication networks may include alocal area network (LAN), a wide area network (WAN), a packet datanetwork (e.g., the Internet), mobile telephone networks (e.g., cellularnetworks), Plain Old Telephone (POTS) networks, and wireless datanetworks (e.g., Institute of Electrical and Electronics Engineers (IEEE)802.11 family of standards known as WiFi®, IEEE 802.16 family ofstandards known as WiMax®), IEEE 802.15.4 family of standards,peer-to-peer (P2P) networks, among others. In an example, the networkinterface device 2820 may include one or more physical jacks (e.g.,Ethernet, coaxial, or phone jacks) or one or more antennas to connect tothe communication network 2826. In an example, the network interfacedevice 2820 may include a plurality of antennas to wirelesslycommunicate using at least one of single-input multiple-output (SIMO),multiple-input multiple-output (MIMO), or multiple-input single-output(MISO) techniques. The term “transmission medium” shall be taken toinclude any intangible medium that is capable of storing, encoding orcarrying instructions for execution by the machine 2800, and includesdigital or analog communications signals or other intangible medium tofacilitate communication of such software.

Additional Notes

The above detailed description includes references to the accompanyingdrawings, which form a part of the detailed description. The drawingsshow, by way of illustration, specific embodiments in which theinvention can be practiced. These embodiments are also referred toherein as “examples.” Such examples can include elements in addition tothose shown or described. However, the present inventors alsocontemplate examples in which only those elements shown or described areprovided. Moreover, the present inventors also contemplate examplesusing any combination or permutation of those elements shown ordescribed (or one or more aspects thereof), either with respect to aparticular example (or one or more aspects thereof), or with respect toother examples (or one or more aspects thereof) shown or describedherein.

In this document, the terms “a” or “an” are used, as is common in patentdocuments, to include one or more than one, independent of any otherinstances or usages of “at least one” or “one or more.” In thisdocument, the term “or” is used to refer to a nonexclusive or, such that“A or B” includes “A but not B,” “B but not A,” and “A and B,” unlessotherwise indicated. In this document, the terms “including” and “inwhich” are used as the plain-English equivalents of the respective terms“comprising” and “wherein.” Also, in the following claims, the terms“including” and “comprising” are open-ended, that is, a system, device,article, composition, formulation, or process that includes elements inaddition to those listed after such a term in a claim are still deemedto fall within the scope of that claim. Moreover, in the followingclaims, the terms “first,” “second,” and “third,” etc. are used merelyas labels, and are not intended to impose numerical requirements ontheir objects.

The above description is intended to be illustrative, and notrestrictive. For example, the above-described examples (or one or moreaspects thereof) may be used in combination with each other. Otherembodiments can be used, such as by one of ordinary skill in the artupon reviewing the above description. The Abstract is provided to complywith 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain thenature of the technical disclosure. It is submitted with theunderstanding that it will not be used to interpret or limit the scopeor meaning of the claims. Also, in the above Detailed Description,various features may be grouped together to streamline the disclosure.This should not be interpreted as intending that an unclaimed disclosedfeature is essential to any claim. Rather, inventive subject matter maylie in less than all features of a particular disclosed embodiment.Thus, the following claims are hereby incorporated into the DetailedDescription as examples or embodiments, with each claim standing on itsown as a separate embodiment, and it is contemplated that suchembodiments can be combined with each other in various combinations orpermutations. The scope of the invention should be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

What is claimed is:
 1. A laser feedback control system coupled to afirst laser system configured to deliver laser energy directed toward atarget tissue, the laser feedback control system comprising: a feedbackanalyzer for receiving signals from a target tissue using aspectroscopic sensor, the signals comprising a first signal indicativeof one or more spectroscopic properties of a target tissue; and a lasercontroller in operative communication with each of the feedback analyzerand the first laser system, the laser controller being configured to:receive the first signal from the feedback analyzer; determine whetherthe first signal generally equals a first preset; and if the firstsignal meets a first preset, send a first control signal to the firstlaser system to change from a first state of the first laser system to asecond state the first laser system.
 2. The laser feedback controlsystem of claim 1, wherein the laser controller is further configured toreceive a second signal from the feedback analyzer, the second signalbeing distinct from the first signal.
 3. The laser feedback controlsystem of claim 2, wherein the laser controller is further configured tosend a second control signal to the first laser system to change fromthe second state of the first laser system to the first state of thefirst laser system if the second signal generally equals a secondpreset.
 4. The laser feedback control system of claim 2, wherein thelaser feedback control system is configured to be connectable to asecond laser system distinct from the first laser system.
 5. The laserfeedback control system of claim 4, wherein, the laser controller isconfigured to independently control the first laser system and thesecond laser system.
 6. The laser feedback control system of claim 5,wherein, the laser controller is configured to send a third controlsignal to the second laser system to change from a first state of thesecond laser system to a second state of the second laser system if thesecond signal generally equals a second preset.
 7. The laser feedbackcontrol system of claim 6, wherein, the laser controller is configuredto send a fourth control signal to the second laser system to changefrom the second state of the second laser system to the first state ofthe second laser system if the laser controller determines that thefirst signal generally equals the first preset.
 8. The laser feedbackcontrol system of claim 7, wherein, if the laser controller determinesthat the first signal meets the first preset, the laser controller isconfigured to send: the first control signal to the first laser system,thereby changing the first laser system from the first state of thefirst laser system to the second state of the first laser system; andthe fourth control signal to the second laser system, thereby changingthe second laser system from the second state of the second laser systemto the first state of the second laser system.
 9. The laser feedbackcontrol system of claim 8, wherein, if the laser controller determinesthat the second signal meets the second preset, the laser controller isconfigured to send: the second control signal to the first laser system,thereby changing the first laser system from the second state of thefirst laser system to the first state of the first laser system; and thethird control signal to the second laser system, thereby changing thesecond laser system from the first state of the second laser system tothe second state of the second laser system.
 10. The laser feedbackcontrol system of claim 1, wherein the spectroscopic sensor includes atleast one of: an imaging camera; a Fourier Transform Infrared (FTIR)spectrometer; a Raman spectrometer; a UV-VIS reflection spectrometer; ora fluorescent spectrometer.
 11. The laser feedback control system ofclaim 1, further comprising a signal detection optical fiber operativelycoupled to the spectroscopic sensor, the signal detection optical fiberbeing configured to transmit the first signal from the target tissue tothe spectroscopic sensor.
 12. The laser feedback control system of claim1, wherein the spectroscopic sensor is in operative communication with afirst optical fiber of the first laser system, the spectroscopic sensorbeing configured to detect the first signal via the first optical fiberof the first laser system.
 13. A laser treatment system, comprising: afirst laser system, comprising: a first laser source, and a firstoptical fiber operatively coupled the first laser source, the firstoptical fiber being configured to deliver energy from the first lasersource toward a target tissue; and a laser feedback control systemcoupled to the first laser system, the laser feedback control systemcomprising: feedback analyzer for receiving signals from the targettissue, the signals comprising a first signal indicative of one or morespectroscopic properties of the target tissue; and a laser controller inoperative communication with each of the feedback analyzer and the firstlaser system, the laser controller being configured to receive the firstsignal from the feedback analyzer, to determine whether the first signalis generally equal to a first preset, and to send a first control signalto the first laser system to change from a first state of the firstlaser system to a second state the first laser system.
 14. The lasertreatment system of claim 13, further comprising a second laser systemthat includes a second laser source in operative communication with thefirst optical fiber.
 15. The laser treatment system of claim 14, whereinthe first laser source is configured to generate a first laser outputover a first wavelength range, and the second laser source is configuredto generate a second laser output over a second wavelength range,distinct from the first wavelength range.
 16. The laser treatment systemof claim 15, wherein the first wavelength range corresponds to at leasta portion of an absorption spectrum of the target tissue, and the secondwavelength range corresponds to at least a portion of an absorptionspectrum of carbonized tissue.
 17. The laser treatment system of claim14, wherein the second laser system is controllable by the lasercontroller, such that upon receipt of control signals from the lasercontroller, the second laser system changes from a first state of thesecond laser system to a second state of the second laser system, orfrom the second state of the second laser system to the first state ofthe second laser system.
 18. The laser treatment system of claim 14,wherein the first state of each of the first laser system and the secondlaser system corresponds to generation of a first laser output by thefirst laser source and a second laser output by a second laser sourcerespectively.
 19. The laser treatment system of claim 14, wherein thesecond state of each of the first laser system and the second lasersystem corresponds to a state where the first laser source and thesecond laser source each do not generate a laser output.
 20. A method ofcontrolling a laser treatment system comprising a first laser system,the method comprising: receiving, using a feedback analyzer, signalsfrom a target tissue, the signals comprising a first signal indicativeof one or more spectroscopic properties of a target tissue; determining,using a laser controller, whether the first signal is generally equal toa first preset; and sending a first control signal to the first lasersystem to change from a first state of the first laser system to asecond state the first laser system if the first signal is generallyequal to the first preset.
 21. The method of claim 20, wherein the firstsignal is indicative of the target tissue being carbonized by absorptionof a first laser output from the first laser system.
 22. The method ofclaim 21, wherein the first state of the first laser system correspondsto a state when the first laser system generates the first laser output,and the second state of the first laser system corresponds to a statewhen the first laser system does not generate the first laser output.23. The method of claim 20, wherein the signals received by the feedbackanalyzer comprises a second signal distinct from the first signal.